diff --git a/bitbake/lib/bs4/element.py b/bitbake/lib/bs4/element.py
new file mode 100644
index 0000000..da9afdf
--- /dev/null
+++ b/bitbake/lib/bs4/element.py
@@ -0,0 +1,1611 @@
+import collections
+import re
+import sys
+import warnings
+from bs4.dammit import EntitySubstitution
+
+DEFAULT_OUTPUT_ENCODING = "utf-8"
+PY3K = (sys.version_info[0] > 2)
+
+whitespace_re = re.compile("\s+")
+
+def _alias(attr):
+    """Alias one attribute name to another for backward compatibility"""
+    @property
+    def alias(self):
+        return getattr(self, attr)
+
+    @alias.setter
+    def alias(self):
+        return setattr(self, attr)
+    return alias
+
+
+class NamespacedAttribute(unicode):
+
+    def __new__(cls, prefix, name, namespace=None):
+        if name is None:
+            obj = unicode.__new__(cls, prefix)
+        elif prefix is None:
+            # Not really namespaced.
+            obj = unicode.__new__(cls, name)
+        else:
+            obj = unicode.__new__(cls, prefix + ":" + name)
+        obj.prefix = prefix
+        obj.name = name
+        obj.namespace = namespace
+        return obj
+
+class AttributeValueWithCharsetSubstitution(unicode):
+    """A stand-in object for a character encoding specified in HTML."""
+
+class CharsetMetaAttributeValue(AttributeValueWithCharsetSubstitution):
+    """A generic stand-in for the value of a meta tag's 'charset' attribute.
+
+    When Beautiful Soup parses the markup '<meta charset="utf8">', the
+    value of the 'charset' attribute will be one of these objects.
+    """
+
+    def __new__(cls, original_value):
+        obj = unicode.__new__(cls, original_value)
+        obj.original_value = original_value
+        return obj
+
+    def encode(self, encoding):
+        return encoding
+
+
+class ContentMetaAttributeValue(AttributeValueWithCharsetSubstitution):
+    """A generic stand-in for the value of a meta tag's 'content' attribute.
+
+    When Beautiful Soup parses the markup:
+     <meta http-equiv="content-type" content="text/html; charset=utf8">
+
+    The value of the 'content' attribute will be one of these objects.
+    """
+
+    CHARSET_RE = re.compile("((^|;)\s*charset=)([^;]*)", re.M)
+
+    def __new__(cls, original_value):
+        match = cls.CHARSET_RE.search(original_value)
+        if match is None:
+            # No substitution necessary.
+            return unicode.__new__(unicode, original_value)
+
+        obj = unicode.__new__(cls, original_value)
+        obj.original_value = original_value
+        return obj
+
+    def encode(self, encoding):
+        def rewrite(match):
+            return match.group(1) + encoding
+        return self.CHARSET_RE.sub(rewrite, self.original_value)
+
+class HTMLAwareEntitySubstitution(EntitySubstitution):
+
+    """Entity substitution rules that are aware of some HTML quirks.
+
+    Specifically, the contents of <script> and <style> tags should not
+    undergo entity substitution.
+
+    Incoming NavigableString objects are checked to see if they're the
+    direct children of a <script> or <style> tag.
+    """
+
+    cdata_containing_tags = set(["script", "style"])
+
+    preformatted_tags = set(["pre"])
+
+    @classmethod
+    def _substitute_if_appropriate(cls, ns, f):
+        if (isinstance(ns, NavigableString)
+            and ns.parent is not None
+            and ns.parent.name in cls.cdata_containing_tags):
+            # Do nothing.
+            return ns
+        # Substitute.
+        return f(ns)
+
+    @classmethod
+    def substitute_html(cls, ns):
+        return cls._substitute_if_appropriate(
+            ns, EntitySubstitution.substitute_html)
+
+    @classmethod
+    def substitute_xml(cls, ns):
+        return cls._substitute_if_appropriate(
+            ns, EntitySubstitution.substitute_xml)
+
+class PageElement(object):
+    """Contains the navigational information for some part of the page
+    (either a tag or a piece of text)"""
+
+    # There are five possible values for the "formatter" argument passed in
+    # to methods like encode() and prettify():
+    #
+    # "html" - All Unicode characters with corresponding HTML entities
+    #   are converted to those entities on output.
+    # "minimal" - Bare ampersands and angle brackets are converted to
+    #   XML entities: &amp; &lt; &gt;
+    # None - The null formatter. Unicode characters are never
+    #   converted to entities.  This is not recommended, but it's
+    #   faster than "minimal".
+    # A function - This function will be called on every string that
+    #  needs to undergo entity substitution.
+    #
+
+    # In an HTML document, the default "html" and "minimal" functions
+    # will leave the contents of <script> and <style> tags alone. For
+    # an XML document, all tags will be given the same treatment.
+
+    HTML_FORMATTERS = {
+        "html" : HTMLAwareEntitySubstitution.substitute_html,
+        "minimal" : HTMLAwareEntitySubstitution.substitute_xml,
+        None : None
+        }
+
+    XML_FORMATTERS = {
+        "html" : EntitySubstitution.substitute_html,
+        "minimal" : EntitySubstitution.substitute_xml,
+        None : None
+        }
+
+    def format_string(self, s, formatter='minimal'):
+        """Format the given string using the given formatter."""
+        if not callable(formatter):
+            formatter = self._formatter_for_name(formatter)
+        if formatter is None:
+            output = s
+        else:
+            output = formatter(s)
+        return output
+
+    @property
+    def _is_xml(self):
+        """Is this element part of an XML tree or an HTML tree?
+
+        This is used when mapping a formatter name ("minimal") to an
+        appropriate function (one that performs entity-substitution on
+        the contents of <script> and <style> tags, or not). It's
+        inefficient, but it should be called very rarely.
+        """
+        if self.parent is None:
+            # This is the top-level object. It should have .is_xml set
+            # from tree creation. If not, take a guess--BS is usually
+            # used on HTML markup.
+            return getattr(self, 'is_xml', False)
+        return self.parent._is_xml
+
+    def _formatter_for_name(self, name):
+        "Look up a formatter function based on its name and the tree."
+        if self._is_xml:
+            return self.XML_FORMATTERS.get(
+                name, EntitySubstitution.substitute_xml)
+        else:
+            return self.HTML_FORMATTERS.get(
+                name, HTMLAwareEntitySubstitution.substitute_xml)
+
+    def setup(self, parent=None, previous_element=None):
+        """Sets up the initial relations between this element and
+        other elements."""
+        self.parent = parent
+        self.previous_element = previous_element
+        if previous_element is not None:
+            self.previous_element.next_element = self
+        self.next_element = None
+        self.previous_sibling = None
+        self.next_sibling = None
+        if self.parent is not None and self.parent.contents:
+            self.previous_sibling = self.parent.contents[-1]
+            self.previous_sibling.next_sibling = self
+
+    nextSibling = _alias("next_sibling")  # BS3
+    previousSibling = _alias("previous_sibling")  # BS3
+
+    def replace_with(self, replace_with):
+        if replace_with is self:
+            return
+        if replace_with is self.parent:
+            raise ValueError("Cannot replace a Tag with its parent.")
+        old_parent = self.parent
+        my_index = self.parent.index(self)
+        self.extract()
+        old_parent.insert(my_index, replace_with)
+        return self
+    replaceWith = replace_with  # BS3
+
+    def unwrap(self):
+        my_parent = self.parent
+        my_index = self.parent.index(self)
+        self.extract()
+        for child in reversed(self.contents[:]):
+            my_parent.insert(my_index, child)
+        return self
+    replace_with_children = unwrap
+    replaceWithChildren = unwrap  # BS3
+
+    def wrap(self, wrap_inside):
+        me = self.replace_with(wrap_inside)
+        wrap_inside.append(me)
+        return wrap_inside
+
+    def extract(self):
+        """Destructively rips this element out of the tree."""
+        if self.parent is not None:
+            del self.parent.contents[self.parent.index(self)]
+
+        #Find the two elements that would be next to each other if
+        #this element (and any children) hadn't been parsed. Connect
+        #the two.
+        last_child = self._last_descendant()
+        next_element = last_child.next_element
+
+        if self.previous_element is not None:
+            self.previous_element.next_element = next_element
+        if next_element is not None:
+            next_element.previous_element = self.previous_element
+        self.previous_element = None
+        last_child.next_element = None
+
+        self.parent = None
+        if self.previous_sibling is not None:
+            self.previous_sibling.next_sibling = self.next_sibling
+        if self.next_sibling is not None:
+            self.next_sibling.previous_sibling = self.previous_sibling
+        self.previous_sibling = self.next_sibling = None
+        return self
+
+    def _last_descendant(self, is_initialized=True, accept_self=True):
+        "Finds the last element beneath this object to be parsed."
+        if is_initialized and self.next_sibling:
+            last_child = self.next_sibling.previous_element
+        else:
+            last_child = self
+            while isinstance(last_child, Tag) and last_child.contents:
+                last_child = last_child.contents[-1]
+        if not accept_self and last_child == self:
+            last_child = None
+        return last_child
+    # BS3: Not part of the API!
+    _lastRecursiveChild = _last_descendant
+
+    def insert(self, position, new_child):
+        if new_child is self:
+            raise ValueError("Cannot insert a tag into itself.")
+        if (isinstance(new_child, basestring)
+            and not isinstance(new_child, NavigableString)):
+            new_child = NavigableString(new_child)
+
+        position = min(position, len(self.contents))
+        if hasattr(new_child, 'parent') and new_child.parent is not None:
+            # We're 'inserting' an element that's already one
+            # of this object's children.
+            if new_child.parent is self:
+                current_index = self.index(new_child)
+                if current_index < position:
+                    # We're moving this element further down the list
+                    # of this object's children. That means that when
+                    # we extract this element, our target index will
+                    # jump down one.
+                    position -= 1
+            new_child.extract()
+
+        new_child.parent = self
+        previous_child = None
+        if position == 0:
+            new_child.previous_sibling = None
+            new_child.previous_element = self
+        else:
+            previous_child = self.contents[position - 1]
+            new_child.previous_sibling = previous_child
+            new_child.previous_sibling.next_sibling = new_child
+            new_child.previous_element = previous_child._last_descendant(False)
+        if new_child.previous_element is not None:
+            new_child.previous_element.next_element = new_child
+
+        new_childs_last_element = new_child._last_descendant(False)
+
+        if position >= len(self.contents):
+            new_child.next_sibling = None
+
+            parent = self
+            parents_next_sibling = None
+            while parents_next_sibling is None and parent is not None:
+                parents_next_sibling = parent.next_sibling
+                parent = parent.parent
+                if parents_next_sibling is not None:
+                    # We found the element that comes next in the document.
+                    break
+            if parents_next_sibling is not None:
+                new_childs_last_element.next_element = parents_next_sibling
+            else:
+                # The last element of this tag is the last element in
+                # the document.
+                new_childs_last_element.next_element = None
+        else:
+            next_child = self.contents[position]
+            new_child.next_sibling = next_child
+            if new_child.next_sibling is not None:
+                new_child.next_sibling.previous_sibling = new_child
+            new_childs_last_element.next_element = next_child
+
+        if new_childs_last_element.next_element is not None:
+            new_childs_last_element.next_element.previous_element = new_childs_last_element
+        self.contents.insert(position, new_child)
+
+    def append(self, tag):
+        """Appends the given tag to the contents of this tag."""
+        self.insert(len(self.contents), tag)
+
+    def insert_before(self, predecessor):
+        """Makes the given element the immediate predecessor of this one.
+
+        The two elements will have the same parent, and the given element
+        will be immediately before this one.
+        """
+        if self is predecessor:
+            raise ValueError("Can't insert an element before itself.")
+        parent = self.parent
+        if parent is None:
+            raise ValueError(
+                "Element has no parent, so 'before' has no meaning.")
+        # Extract first so that the index won't be screwed up if they
+        # are siblings.
+        if isinstance(predecessor, PageElement):
+            predecessor.extract()
+        index = parent.index(self)
+        parent.insert(index, predecessor)
+
+    def insert_after(self, successor):
+        """Makes the given element the immediate successor of this one.
+
+        The two elements will have the same parent, and the given element
+        will be immediately after this one.
+        """
+        if self is successor:
+            raise ValueError("Can't insert an element after itself.")
+        parent = self.parent
+        if parent is None:
+            raise ValueError(
+                "Element has no parent, so 'after' has no meaning.")
+        # Extract first so that the index won't be screwed up if they
+        # are siblings.
+        if isinstance(successor, PageElement):
+            successor.extract()
+        index = parent.index(self)
+        parent.insert(index+1, successor)
+
+    def find_next(self, name=None, attrs={}, text=None, **kwargs):
+        """Returns the first item that matches the given criteria and
+        appears after this Tag in the document."""
+        return self._find_one(self.find_all_next, name, attrs, text, **kwargs)
+    findNext = find_next  # BS3
+
+    def find_all_next(self, name=None, attrs={}, text=None, limit=None,
+                    **kwargs):
+        """Returns all items that match the given criteria and appear
+        after this Tag in the document."""
+        return self._find_all(name, attrs, text, limit, self.next_elements,
+                             **kwargs)
+    findAllNext = find_all_next  # BS3
+
+    def find_next_sibling(self, name=None, attrs={}, text=None, **kwargs):
+        """Returns the closest sibling to this Tag that matches the
+        given criteria and appears after this Tag in the document."""
+        return self._find_one(self.find_next_siblings, name, attrs, text,
+                             **kwargs)
+    findNextSibling = find_next_sibling  # BS3
+
+    def find_next_siblings(self, name=None, attrs={}, text=None, limit=None,
+                           **kwargs):
+        """Returns the siblings of this Tag that match the given
+        criteria and appear after this Tag in the document."""
+        return self._find_all(name, attrs, text, limit,
+                              self.next_siblings, **kwargs)
+    findNextSiblings = find_next_siblings   # BS3
+    fetchNextSiblings = find_next_siblings  # BS2
+
+    def find_previous(self, name=None, attrs={}, text=None, **kwargs):
+        """Returns the first item that matches the given criteria and
+        appears before this Tag in the document."""
+        return self._find_one(
+            self.find_all_previous, name, attrs, text, **kwargs)
+    findPrevious = find_previous  # BS3
+
+    def find_all_previous(self, name=None, attrs={}, text=None, limit=None,
+                        **kwargs):
+        """Returns all items that match the given criteria and appear
+        before this Tag in the document."""
+        return self._find_all(name, attrs, text, limit, self.previous_elements,
+                           **kwargs)
+    findAllPrevious = find_all_previous  # BS3
+    fetchPrevious = find_all_previous    # BS2
+
+    def find_previous_sibling(self, name=None, attrs={}, text=None, **kwargs):
+        """Returns the closest sibling to this Tag that matches the
+        given criteria and appears before this Tag in the document."""
+        return self._find_one(self.find_previous_siblings, name, attrs, text,
+                             **kwargs)
+    findPreviousSibling = find_previous_sibling  # BS3
+
+    def find_previous_siblings(self, name=None, attrs={}, text=None,
+                               limit=None, **kwargs):
+        """Returns the siblings of this Tag that match the given
+        criteria and appear before this Tag in the document."""
+        return self._find_all(name, attrs, text, limit,
+                              self.previous_siblings, **kwargs)
+    findPreviousSiblings = find_previous_siblings   # BS3
+    fetchPreviousSiblings = find_previous_siblings  # BS2
+
+    def find_parent(self, name=None, attrs={}, **kwargs):
+        """Returns the closest parent of this Tag that matches the given
+        criteria."""
+        # NOTE: We can't use _find_one because findParents takes a different
+        # set of arguments.
+        r = None
+        l = self.find_parents(name, attrs, 1, **kwargs)
+        if l:
+            r = l[0]
+        return r
+    findParent = find_parent  # BS3
+
+    def find_parents(self, name=None, attrs={}, limit=None, **kwargs):
+        """Returns the parents of this Tag that match the given
+        criteria."""
+
+        return self._find_all(name, attrs, None, limit, self.parents,
+                             **kwargs)
+    findParents = find_parents   # BS3
+    fetchParents = find_parents  # BS2
+
+    @property
+    def next(self):
+        return self.next_element
+
+    @property
+    def previous(self):
+        return self.previous_element
+
+    #These methods do the real heavy lifting.
+
+    def _find_one(self, method, name, attrs, text, **kwargs):
+        r = None
+        l = method(name, attrs, text, 1, **kwargs)
+        if l:
+            r = l[0]
+        return r
+
+    def _find_all(self, name, attrs, text, limit, generator, **kwargs):
+        "Iterates over a generator looking for things that match."
+
+        if isinstance(name, SoupStrainer):
+            strainer = name
+        else:
+            strainer = SoupStrainer(name, attrs, text, **kwargs)
+
+        if text is None and not limit and not attrs and not kwargs:
+            if name is True or name is None:
+                # Optimization to find all tags.
+                result = (element for element in generator
+                          if isinstance(element, Tag))
+                return ResultSet(strainer, result)
+            elif isinstance(name, basestring):
+                # Optimization to find all tags with a given name.
+                result = (element for element in generator
+                          if isinstance(element, Tag)
+                            and element.name == name)
+                return ResultSet(strainer, result)
+        results = ResultSet(strainer)
+        while True:
+            try:
+                i = next(generator)
+            except StopIteration:
+                break
+            if i:
+                found = strainer.search(i)
+                if found:
+                    results.append(found)
+                    if limit and len(results) >= limit:
+                        break
+        return results
+
+    #These generators can be used to navigate starting from both
+    #NavigableStrings and Tags.
+    @property
+    def next_elements(self):
+        i = self.next_element
+        while i is not None:
+            yield i
+            i = i.next_element
+
+    @property
+    def next_siblings(self):
+        i = self.next_sibling
+        while i is not None:
+            yield i
+            i = i.next_sibling
+
+    @property
+    def previous_elements(self):
+        i = self.previous_element
+        while i is not None:
+            yield i
+            i = i.previous_element
+
+    @property
+    def previous_siblings(self):
+        i = self.previous_sibling
+        while i is not None:
+            yield i
+            i = i.previous_sibling
+
+    @property
+    def parents(self):
+        i = self.parent
+        while i is not None:
+            yield i
+            i = i.parent
+
+    # Methods for supporting CSS selectors.
+
+    tag_name_re = re.compile('^[a-z0-9]+$')
+
+    # /^(\w+)\[(\w+)([=~\|\^\$\*]?)=?"?([^\]"]*)"?\]$/
+    #   \---/  \---/\-------------/    \-------/
+    #     |      |         |               |
+    #     |      |         |           The value
+    #     |      |    ~,|,^,$,* or =
+    #     |   Attribute
+    #    Tag
+    attribselect_re = re.compile(
+        r'^(?P<tag>\w+)?\[(?P<attribute>\w+)(?P<operator>[=~\|\^\$\*]?)' +
+        r'=?"?(?P<value>[^\]"]*)"?\]$'
+        )
+
+    def _attr_value_as_string(self, value, default=None):
+        """Force an attribute value into a string representation.
+
+        A multi-valued attribute will be converted into a
+        space-separated stirng.
+        """
+        value = self.get(value, default)
+        if isinstance(value, list) or isinstance(value, tuple):
+            value =" ".join(value)
+        return value
+
+    def _tag_name_matches_and(self, function, tag_name):
+        if not tag_name:
+            return function
+        else:
+            def _match(tag):
+                return tag.name == tag_name and function(tag)
+            return _match
+
+    def _attribute_checker(self, operator, attribute, value=''):
+        """Create a function that performs a CSS selector operation.
+
+        Takes an operator, attribute and optional value. Returns a
+        function that will return True for elements that match that
+        combination.
+        """
+        if operator == '=':
+            # string representation of `attribute` is equal to `value`
+            return lambda el: el._attr_value_as_string(attribute) == value
+        elif operator == '~':
+            # space-separated list representation of `attribute`
+            # contains `value`
+            def _includes_value(element):
+                attribute_value = element.get(attribute, [])
+                if not isinstance(attribute_value, list):
+                    attribute_value = attribute_value.split()
+                return value in attribute_value
+            return _includes_value
+        elif operator == '^':
+            # string representation of `attribute` starts with `value`
+            return lambda el: el._attr_value_as_string(
+                attribute, '').startswith(value)
+        elif operator == '$':
+            # string represenation of `attribute` ends with `value`
+            return lambda el: el._attr_value_as_string(
+                attribute, '').endswith(value)
+        elif operator == '*':
+            # string representation of `attribute` contains `value`
+            return lambda el: value in el._attr_value_as_string(attribute, '')
+        elif operator == '|':
+            # string representation of `attribute` is either exactly
+            # `value` or starts with `value` and then a dash.
+            def _is_or_starts_with_dash(element):
+                attribute_value = element._attr_value_as_string(attribute, '')
+                return (attribute_value == value or attribute_value.startswith(
+                        value + '-'))
+            return _is_or_starts_with_dash
+        else:
+            return lambda el: el.has_attr(attribute)
+
+    # Old non-property versions of the generators, for backwards
+    # compatibility with BS3.
+    def nextGenerator(self):
+        return self.next_elements
+
+    def nextSiblingGenerator(self):
+        return self.next_siblings
+
+    def previousGenerator(self):
+        return self.previous_elements
+
+    def previousSiblingGenerator(self):
+        return self.previous_siblings
+
+    def parentGenerator(self):
+        return self.parents
+
+
+class NavigableString(unicode, PageElement):
+
+    PREFIX = ''
+    SUFFIX = ''
+
+    def __new__(cls, value):
+        """Create a new NavigableString.
+
+        When unpickling a NavigableString, this method is called with
+        the string in DEFAULT_OUTPUT_ENCODING. That encoding needs to be
+        passed in to the superclass's __new__ or the superclass won't know
+        how to handle non-ASCII characters.
+        """
+        if isinstance(value, unicode):
+            return unicode.__new__(cls, value)
+        return unicode.__new__(cls, value, DEFAULT_OUTPUT_ENCODING)
+
+    def __copy__(self):
+        return self
+
+    def __getnewargs__(self):
+        return (unicode(self),)
+
+    def __getattr__(self, attr):
+        """text.string gives you text. This is for backwards
+        compatibility for Navigable*String, but for CData* it lets you
+        get the string without the CData wrapper."""
+        if attr == 'string':
+            return self
+        else:
+            raise AttributeError(
+                "'%s' object has no attribute '%s'" % (
+                    self.__class__.__name__, attr))
+
+    def output_ready(self, formatter="minimal"):
+        output = self.format_string(self, formatter)
+        return self.PREFIX + output + self.SUFFIX
+
+    @property
+    def name(self):
+        return None
+
+    @name.setter
+    def name(self, name):
+        raise AttributeError("A NavigableString cannot be given a name.")
+
+class PreformattedString(NavigableString):
+    """A NavigableString not subject to the normal formatting rules.
+
+    The string will be passed into the formatter (to trigger side effects),
+    but the return value will be ignored.
+    """
+
+    def output_ready(self, formatter="minimal"):
+        """CData strings are passed into the formatter.
+        But the return value is ignored."""
+        self.format_string(self, formatter)
+        return self.PREFIX + self + self.SUFFIX
+
+class CData(PreformattedString):
+
+    PREFIX = u'<![CDATA['
+    SUFFIX = u']]>'
+
+class ProcessingInstruction(PreformattedString):
+
+    PREFIX = u'<?'
+    SUFFIX = u'?>'
+
+class Comment(PreformattedString):
+
+    PREFIX = u'<!--'
+    SUFFIX = u'-->'
+
+
+class Declaration(PreformattedString):
+    PREFIX = u'<!'
+    SUFFIX = u'!>'
+
+
+class Doctype(PreformattedString):
+
+    @classmethod
+    def for_name_and_ids(cls, name, pub_id, system_id):
+        value = name or ''
+        if pub_id is not None:
+            value += ' PUBLIC "%s"' % pub_id
+            if system_id is not None:
+                value += ' "%s"' % system_id
+        elif system_id is not None:
+            value += ' SYSTEM "%s"' % system_id
+
+        return Doctype(value)
+
+    PREFIX = u'<!DOCTYPE '
+    SUFFIX = u'>\n'
+
+
+class Tag(PageElement):
+
+    """Represents a found HTML tag with its attributes and contents."""
+
+    def __init__(self, parser=None, builder=None, name=None, namespace=None,
+                 prefix=None, attrs=None, parent=None, previous=None):
+        "Basic constructor."
+
+        if parser is None:
+            self.parser_class = None
+        else:
+            # We don't actually store the parser object: that lets extracted
+            # chunks be garbage-collected.
+            self.parser_class = parser.__class__
+        if name is None:
+            raise ValueError("No value provided for new tag's name.")
+        self.name = name
+        self.namespace = namespace
+        self.prefix = prefix
+        if attrs is None:
+            attrs = {}
+        elif attrs and builder.cdata_list_attributes:
+            attrs = builder._replace_cdata_list_attribute_values(
+                self.name, attrs)
+        else:
+            attrs = dict(attrs)
+        self.attrs = attrs
+        self.contents = []
+        self.setup(parent, previous)
+        self.hidden = False
+
+        # Set up any substitutions, such as the charset in a META tag.
+        if builder is not None:
+            builder.set_up_substitutions(self)
+            self.can_be_empty_element = builder.can_be_empty_element(name)
+        else:
+            self.can_be_empty_element = False
+
+    parserClass = _alias("parser_class")  # BS3
+
+    @property
+    def is_empty_element(self):
+        """Is this tag an empty-element tag? (aka a self-closing tag)
+
+        A tag that has contents is never an empty-element tag.
+
+        A tag that has no contents may or may not be an empty-element
+        tag. It depends on the builder used to create the tag. If the
+        builder has a designated list of empty-element tags, then only
+        a tag whose name shows up in that list is considered an
+        empty-element tag.
+
+        If the builder has no designated list of empty-element tags,
+        then any tag with no contents is an empty-element tag.
+        """
+        return len(self.contents) == 0 and self.can_be_empty_element
+    isSelfClosing = is_empty_element  # BS3
+
+    @property
+    def string(self):
+        """Convenience property to get the single string within this tag.
+
+        :Return: If this tag has a single string child, return value
+         is that string. If this tag has no children, or more than one
+         child, return value is None. If this tag has one child tag,
+         return value is the 'string' attribute of the child tag,
+         recursively.
+        """
+        if len(self.contents) != 1:
+            return None
+        child = self.contents[0]
+        if isinstance(child, NavigableString):
+            return child
+        return child.string
+
+    @string.setter
+    def string(self, string):
+        self.clear()
+        self.append(string.__class__(string))
+
+    def _all_strings(self, strip=False, types=(NavigableString, CData)):
+        """Yield all strings of certain classes, possibly stripping them.
+
+        By default, yields only NavigableString and CData objects. So
+        no comments, processing instructions, etc.
+        """
+        for descendant in self.descendants:
+            if (
+                (types is None and not isinstance(descendant, NavigableString))
+                or
+                (types is not None and type(descendant) not in types)):
+                continue
+            if strip:
+                descendant = descendant.strip()
+                if len(descendant) == 0:
+                    continue
+            yield descendant
+
+    strings = property(_all_strings)
+
+    @property
+    def stripped_strings(self):
+        for string in self._all_strings(True):
+            yield string
+
+    def get_text(self, separator=u"", strip=False,
+                 types=(NavigableString, CData)):
+        """
+        Get all child strings, concatenated using the given separator.
+        """
+        return separator.join([s for s in self._all_strings(
+                    strip, types=types)])
+    getText = get_text
+    text = property(get_text)
+
+    def decompose(self):
+        """Recursively destroys the contents of this tree."""
+        self.extract()
+        i = self
+        while i is not None:
+            next = i.next_element
+            i.__dict__.clear()
+            i.contents = []
+            i = next
+
+    def clear(self, decompose=False):
+        """
+        Extract all children. If decompose is True, decompose instead.
+        """
+        if decompose:
+            for element in self.contents[:]:
+                if isinstance(element, Tag):
+                    element.decompose()
+                else:
+                    element.extract()
+        else:
+            for element in self.contents[:]:
+                element.extract()
+
+    def index(self, element):
+        """
+        Find the index of a child by identity, not value. Avoids issues with
+        tag.contents.index(element) getting the index of equal elements.
+        """
+        for i, child in enumerate(self.contents):
+            if child is element:
+                return i
+        raise ValueError("Tag.index: element not in tag")
+
+    def get(self, key, default=None):
+        """Returns the value of the 'key' attribute for the tag, or
+        the value given for 'default' if it doesn't have that
+        attribute."""
+        return self.attrs.get(key, default)
+
+    def has_attr(self, key):
+        return key in self.attrs
+
+    def __hash__(self):
+        return str(self).__hash__()
+
+    def __getitem__(self, key):
+        """tag[key] returns the value of the 'key' attribute for the tag,
+        and throws an exception if it's not there."""
+        return self.attrs[key]
+
+    def __iter__(self):
+        "Iterating over a tag iterates over its contents."
+        return iter(self.contents)
+
+    def __len__(self):
+        "The length of a tag is the length of its list of contents."
+        return len(self.contents)
+
+    def __contains__(self, x):
+        return x in self.contents
+
+    def __nonzero__(self):
+        "A tag is non-None even if it has no contents."
+        return True
+
+    def __setitem__(self, key, value):
+        """Setting tag[key] sets the value of the 'key' attribute for the
+        tag."""
+        self.attrs[key] = value
+
+    def __delitem__(self, key):
+        "Deleting tag[key] deletes all 'key' attributes for the tag."
+        self.attrs.pop(key, None)
+
+    def __call__(self, *args, **kwargs):
+        """Calling a tag like a function is the same as calling its
+        find_all() method. Eg. tag('a') returns a list of all the A tags
+        found within this tag."""
+        return self.find_all(*args, **kwargs)
+
+    def __getattr__(self, tag):
+        #print "Getattr %s.%s" % (self.__class__, tag)
+        if len(tag) > 3 and tag.endswith('Tag'):
+            # BS3: soup.aTag -> "soup.find("a")
+            tag_name = tag[:-3]
+            warnings.warn(
+                '.%sTag is deprecated, use .find("%s") instead.' % (
+                    tag_name, tag_name))
+            return self.find(tag_name)
+        # We special case contents to avoid recursion.
+        elif not tag.startswith("__") and not tag=="contents":
+            return self.find(tag)
+        raise AttributeError(
+            "'%s' object has no attribute '%s'" % (self.__class__, tag))
+
+    def __eq__(self, other):
+        """Returns true iff this tag has the same name, the same attributes,
+        and the same contents (recursively) as the given tag."""
+        if self is other:
+            return True
+        if (not hasattr(other, 'name') or
+            not hasattr(other, 'attrs') or
+            not hasattr(other, 'contents') or
+            self.name != other.name or
+            self.attrs != other.attrs or
+            len(self) != len(other)):
+            return False
+        for i, my_child in enumerate(self.contents):
+            if my_child != other.contents[i]:
+                return False
+        return True
+
+    def __ne__(self, other):
+        """Returns true iff this tag is not identical to the other tag,
+        as defined in __eq__."""
+        return not self == other
+
+    def __repr__(self, encoding=DEFAULT_OUTPUT_ENCODING):
+        """Renders this tag as a string."""
+        return self.encode(encoding)
+
+    def __unicode__(self):
+        return self.decode()
+
+    def __str__(self):
+        return self.encode()
+
+    if PY3K:
+        __str__ = __repr__ = __unicode__
+
+    def encode(self, encoding=DEFAULT_OUTPUT_ENCODING,
+               indent_level=None, formatter="minimal",
+               errors="xmlcharrefreplace"):
+        # Turn the data structure into Unicode, then encode the
+        # Unicode.
+        u = self.decode(indent_level, encoding, formatter)
+        return u.encode(encoding, errors)
+
+    def _should_pretty_print(self, indent_level):
+        """Should this tag be pretty-printed?"""
+        return (
+            indent_level is not None and
+            (self.name not in HTMLAwareEntitySubstitution.preformatted_tags
+             or self._is_xml))
+
+    def decode(self, indent_level=None,
+               eventual_encoding=DEFAULT_OUTPUT_ENCODING,
+               formatter="minimal"):
+        """Returns a Unicode representation of this tag and its contents.
+
+        :param eventual_encoding: The tag is destined to be
+           encoded into this encoding. This method is _not_
+           responsible for performing that encoding. This information
+           is passed in so that it can be substituted in if the
+           document contains a <META> tag that mentions the document's
+           encoding.
+        """
+
+        # First off, turn a string formatter into a function. This
+        # will stop the lookup from happening over and over again.
+        if not callable(formatter):
+            formatter = self._formatter_for_name(formatter)
+
+        attrs = []
+        if self.attrs:
+            for key, val in sorted(self.attrs.items()):
+                if val is None:
+                    decoded = key
+                else:
+                    if isinstance(val, list) or isinstance(val, tuple):
+                        val = ' '.join(val)
+                    elif not isinstance(val, basestring):
+                        val = unicode(val)
+                    elif (
+                        isinstance(val, AttributeValueWithCharsetSubstitution)
+                        and eventual_encoding is not None):
+                        val = val.encode(eventual_encoding)
+
+                    text = self.format_string(val, formatter)
+                    decoded = (
+                        unicode(key) + '='
+                        + EntitySubstitution.quoted_attribute_value(text))
+                attrs.append(decoded)
+        close = ''
+        closeTag = ''
+
+        prefix = ''
+        if self.prefix:
+            prefix = self.prefix + ":"
+
+        if self.is_empty_element:
+            close = '/'
+        else:
+            closeTag = '</%s%s>' % (prefix, self.name)
+
+        pretty_print = self._should_pretty_print(indent_level)
+        space = ''
+        indent_space = ''
+        if indent_level is not None:
+            indent_space = (' ' * (indent_level - 1))
+        if pretty_print:
+            space = indent_space
+            indent_contents = indent_level + 1
+        else:
+            indent_contents = None
+        contents = self.decode_contents(
+            indent_contents, eventual_encoding, formatter)
+
+        if self.hidden:
+            # This is the 'document root' object.
+            s = contents
+        else:
+            s = []
+            attribute_string = ''
+            if attrs:
+                attribute_string = ' ' + ' '.join(attrs)
+            if indent_level is not None:
+                # Even if this particular tag is not pretty-printed,
+                # we should indent up to the start of the tag.
+                s.append(indent_space)
+            s.append('<%s%s%s%s>' % (
+                    prefix, self.name, attribute_string, close))
+            if pretty_print:
+                s.append("\n")
+            s.append(contents)
+            if pretty_print and contents and contents[-1] != "\n":
+                s.append("\n")
+            if pretty_print and closeTag:
+                s.append(space)
+            s.append(closeTag)
+            if indent_level is not None and closeTag and self.next_sibling:
+                # Even if this particular tag is not pretty-printed,
+                # we're now done with the tag, and we should add a
+                # newline if appropriate.
+                s.append("\n")
+            s = ''.join(s)
+        return s
+
+    def prettify(self, encoding=None, formatter="minimal"):
+        if encoding is None:
+            return self.decode(True, formatter=formatter)
+        else:
+            return self.encode(encoding, True, formatter=formatter)
+
+    def decode_contents(self, indent_level=None,
+                       eventual_encoding=DEFAULT_OUTPUT_ENCODING,
+                       formatter="minimal"):
+        """Renders the contents of this tag as a Unicode string.
+
+        :param eventual_encoding: The tag is destined to be
+           encoded into this encoding. This method is _not_
+           responsible for performing that encoding. This information
+           is passed in so that it can be substituted in if the
+           document contains a <META> tag that mentions the document's
+           encoding.
+        """
+        # First off, turn a string formatter into a function. This
+        # will stop the lookup from happening over and over again.
+        if not callable(formatter):
+            formatter = self._formatter_for_name(formatter)
+
+        pretty_print = (indent_level is not None)
+        s = []
+        for c in self:
+            text = None
+            if isinstance(c, NavigableString):
+                text = c.output_ready(formatter)
+            elif isinstance(c, Tag):
+                s.append(c.decode(indent_level, eventual_encoding,
+                                  formatter))
+            if text and indent_level and not self.name == 'pre':
+                text = text.strip()
+            if text:
+                if pretty_print and not self.name == 'pre':
+                    s.append(" " * (indent_level - 1))
+                s.append(text)
+                if pretty_print and not self.name == 'pre':
+                    s.append("\n")
+        return ''.join(s)
+
+    def encode_contents(
+        self, indent_level=None, encoding=DEFAULT_OUTPUT_ENCODING,
+        formatter="minimal"):
+        """Renders the contents of this tag as a bytestring."""
+        contents = self.decode_contents(indent_level, encoding, formatter)
+        return contents.encode(encoding)
+
+    # Old method for BS3 compatibility
+    def renderContents(self, encoding=DEFAULT_OUTPUT_ENCODING,
+                       prettyPrint=False, indentLevel=0):
+        if not prettyPrint:
+            indentLevel = None
+        return self.encode_contents(
+            indent_level=indentLevel, encoding=encoding)
+
+    #Soup methods
+
+    def find(self, name=None, attrs={}, recursive=True, text=None,
+             **kwargs):
+        """Return only the first child of this Tag matching the given
+        criteria."""
+        r = None
+        l = self.find_all(name, attrs, recursive, text, 1, **kwargs)
+        if l:
+            r = l[0]
+        return r
+    findChild = find
+
+    def find_all(self, name=None, attrs={}, recursive=True, text=None,
+                 limit=None, **kwargs):
+        """Extracts a list of Tag objects that match the given
+        criteria.  You can specify the name of the Tag and any
+        attributes you want the Tag to have.
+
+        The value of a key-value pair in the 'attrs' map can be a
+        string, a list of strings, a regular expression object, or a
+        callable that takes a string and returns whether or not the
+        string matches for some custom definition of 'matches'. The
+        same is true of the tag name."""
+
+        generator = self.descendants
+        if not recursive:
+            generator = self.children
+        return self._find_all(name, attrs, text, limit, generator, **kwargs)
+    findAll = find_all       # BS3
+    findChildren = find_all  # BS2
+
+    #Generator methods
+    @property
+    def children(self):
+        # return iter() to make the purpose of the method clear
+        return iter(self.contents)  # XXX This seems to be untested.
+
+    @property
+    def descendants(self):
+        if not len(self.contents):
+            return
+        stopNode = self._last_descendant().next_element
+        current = self.contents[0]
+        while current is not stopNode:
+            yield current
+            current = current.next_element
+
+    # CSS selector code
+
+    _selector_combinators = ['>', '+', '~']
+    _select_debug = False
+    def select(self, selector, _candidate_generator=None):
+        """Perform a CSS selection operation on the current element."""
+        tokens = selector.split()
+        current_context = [self]
+
+        if tokens[-1] in self._selector_combinators:
+            raise ValueError(
+                'Final combinator "%s" is missing an argument.' % tokens[-1])
+        if self._select_debug:
+            print 'Running CSS selector "%s"' % selector
+        for index, token in enumerate(tokens):
+            if self._select_debug:
+                print ' Considering token "%s"' % token
+            recursive_candidate_generator = None
+            tag_name = None
+            if tokens[index-1] in self._selector_combinators:
+                # This token was consumed by the previous combinator. Skip it.
+                if self._select_debug:
+                    print '  Token was consumed by the previous combinator.'
+                continue
+            # Each operation corresponds to a checker function, a rule
+            # for determining whether a candidate matches the
+            # selector. Candidates are generated by the active
+            # iterator.
+            checker = None
+
+            m = self.attribselect_re.match(token)
+            if m is not None:
+                # Attribute selector
+                tag_name, attribute, operator, value = m.groups()
+                checker = self._attribute_checker(operator, attribute, value)
+
+            elif '#' in token:
+                # ID selector
+                tag_name, tag_id = token.split('#', 1)
+                def id_matches(tag):
+                    return tag.get('id', None) == tag_id
+                checker = id_matches
+
+            elif '.' in token:
+                # Class selector
+                tag_name, klass = token.split('.', 1)
+                classes = set(klass.split('.'))
+                def classes_match(candidate):
+                    return classes.issubset(candidate.get('class', []))
+                checker = classes_match
+
+            elif ':' in token:
+                # Pseudo-class
+                tag_name, pseudo = token.split(':', 1)
+                if tag_name == '':
+                    raise ValueError(
+                        "A pseudo-class must be prefixed with a tag name.")
+                pseudo_attributes = re.match('([a-zA-Z\d-]+)\(([a-zA-Z\d]+)\)', pseudo)
+                found = []
+                if pseudo_attributes is not None:
+                    pseudo_type, pseudo_value = pseudo_attributes.groups()
+                    if pseudo_type == 'nth-of-type':
+                        try:
+                            pseudo_value = int(pseudo_value)
+                        except:
+                            raise NotImplementedError(
+                                'Only numeric values are currently supported for the nth-of-type pseudo-class.')
+                        if pseudo_value < 1:
+                            raise ValueError(
+                                'nth-of-type pseudo-class value must be at least 1.')
+                        class Counter(object):
+                            def __init__(self, destination):
+                                self.count = 0
+                                self.destination = destination
+
+                            def nth_child_of_type(self, tag):
+                                self.count += 1
+                                if self.count == self.destination:
+                                    return True
+                                if self.count > self.destination:
+                                    # Stop the generator that's sending us
+                                    # these things.
+                                    raise StopIteration()
+                                return False
+                        checker = Counter(pseudo_value).nth_child_of_type
+                    else:
+                        raise NotImplementedError(
+                            'Only the following pseudo-classes are implemented: nth-of-type.')
+
+            elif token == '*':
+                # Star selector -- matches everything
+                pass
+            elif token == '>':
+                # Run the next token as a CSS selector against the
+                # direct children of each tag in the current context.
+                recursive_candidate_generator = lambda tag: tag.children
+            elif token == '~':
+                # Run the next token as a CSS selector against the
+                # siblings of each tag in the current context.
+                recursive_candidate_generator = lambda tag: tag.next_siblings
+            elif token == '+':
+                # For each tag in the current context, run the next
+                # token as a CSS selector against the tag's next
+                # sibling that's a tag.
+                def next_tag_sibling(tag):
+                    yield tag.find_next_sibling(True)
+                recursive_candidate_generator = next_tag_sibling
+
+            elif self.tag_name_re.match(token):
+                # Just a tag name.
+                tag_name = token
+            else:
+                raise ValueError(
+                    'Unsupported or invalid CSS selector: "%s"' % token)
+
+            if recursive_candidate_generator:
+                # This happens when the selector looks like  "> foo".
+                #
+                # The generator calls select() recursively on every
+                # member of the current context, passing in a different
+                # candidate generator and a different selector.
+                #
+                # In the case of "> foo", the candidate generator is
+                # one that yields a tag's direct children (">"), and
+                # the selector is "foo".
+                next_token = tokens[index+1]
+                def recursive_select(tag):
+                    if self._select_debug:
+                        print '    Calling select("%s") recursively on %s %s' % (next_token, tag.name, tag.attrs)
+                        print '-' * 40
+                    for i in tag.select(next_token, recursive_candidate_generator):
+                        if self._select_debug:
+                            print '(Recursive select picked up candidate %s %s)' % (i.name, i.attrs)
+                        yield i
+                    if self._select_debug:
+                        print '-' * 40
+                _use_candidate_generator = recursive_select
+            elif _candidate_generator is None:
+                # By default, a tag's candidates are all of its
+                # children. If tag_name is defined, only yield tags
+                # with that name.
+                if self._select_debug:
+                    if tag_name:
+                        check = "[any]"
+                    else:
+                        check = tag_name
+                    print '   Default candidate generator, tag name="%s"' % check
+                if self._select_debug:
+                    # This is redundant with later code, but it stops
+                    # a bunch of bogus tags from cluttering up the
+                    # debug log.
+                    def default_candidate_generator(tag):
+                        for child in tag.descendants:
+                            if not isinstance(child, Tag):
+                                continue
+                            if tag_name and not child.name == tag_name:
+                                continue
+                            yield child
+                    _use_candidate_generator = default_candidate_generator
+                else:
+                    _use_candidate_generator = lambda tag: tag.descendants
+            else:
+                _use_candidate_generator = _candidate_generator
+
+            new_context = []
+            new_context_ids = set([])
+            for tag in current_context:
+                if self._select_debug:
+                    print "    Running candidate generator on %s %s" % (
+                        tag.name, repr(tag.attrs))
+                for candidate in _use_candidate_generator(tag):
+                    if not isinstance(candidate, Tag):
+                        continue
+                    if tag_name and candidate.name != tag_name:
+                        continue
+                    if checker is not None:
+                        try:
+                            result = checker(candidate)
+                        except StopIteration:
+                            # The checker has decided we should no longer
+                            # run the generator.
+                            break
+                    if checker is None or result:
+                        if self._select_debug:
+                            print "     SUCCESS %s %s" % (candidate.name, repr(candidate.attrs))
+                        if id(candidate) not in new_context_ids:
+                            # If a tag matches a selector more than once,
+                            # don't include it in the context more than once.
+                            new_context.append(candidate)
+                            new_context_ids.add(id(candidate))
+                    elif self._select_debug:
+                        print "     FAILURE %s %s" % (candidate.name, repr(candidate.attrs))
+
+            current_context = new_context
+
+        if self._select_debug:
+            print "Final verdict:"
+            for i in current_context:
+                print " %s %s" % (i.name, i.attrs)
+        return current_context
+
+    # Old names for backwards compatibility
+    def childGenerator(self):
+        return self.children
+
+    def recursiveChildGenerator(self):
+        return self.descendants
+
+    def has_key(self, key):
+        """This was kind of misleading because has_key() (attributes)
+        was different from __in__ (contents). has_key() is gone in
+        Python 3, anyway."""
+        warnings.warn('has_key is deprecated. Use has_attr("%s") instead.' % (
+                key))
+        return self.has_attr(key)
+
+# Next, a couple classes to represent queries and their results.
+class SoupStrainer(object):
+    """Encapsulates a number of ways of matching a markup element (tag or
+    text)."""
+
+    def __init__(self, name=None, attrs={}, text=None, **kwargs):
+        self.name = self._normalize_search_value(name)
+        if not isinstance(attrs, dict):
+            # Treat a non-dict value for attrs as a search for the 'class'
+            # attribute.
+            kwargs['class'] = attrs
+            attrs = None
+
+        if 'class_' in kwargs:
+            # Treat class_="foo" as a search for the 'class'
+            # attribute, overriding any non-dict value for attrs.
+            kwargs['class'] = kwargs['class_']
+            del kwargs['class_']
+
+        if kwargs:
+            if attrs:
+                attrs = attrs.copy()
+                attrs.update(kwargs)
+            else:
+                attrs = kwargs
+        normalized_attrs = {}
+        for key, value in attrs.items():
+            normalized_attrs[key] = self._normalize_search_value(value)
+
+        self.attrs = normalized_attrs
+        self.text = self._normalize_search_value(text)
+
+    def _normalize_search_value(self, value):
+        # Leave it alone if it's a Unicode string, a callable, a
+        # regular expression, a boolean, or None.
+        if (isinstance(value, unicode) or callable(value) or hasattr(value, 'match')
+            or isinstance(value, bool) or value is None):
+            return value
+
+        # If it's a bytestring, convert it to Unicode, treating it as UTF-8.
+        if isinstance(value, bytes):
+            return value.decode("utf8")
+
+        # If it's listlike, convert it into a list of strings.
+        if hasattr(value, '__iter__'):
+            new_value = []
+            for v in value:
+                if (hasattr(v, '__iter__') and not isinstance(v, bytes)
+                    and not isinstance(v, unicode)):
+                    # This is almost certainly the user's mistake. In the
+                    # interests of avoiding infinite loops, we'll let
+                    # it through as-is rather than doing a recursive call.
+                    new_value.append(v)
+                else:
+                    new_value.append(self._normalize_search_value(v))
+            return new_value
+
+        # Otherwise, convert it into a Unicode string.
+        # The unicode(str()) thing is so this will do the same thing on Python 2
+        # and Python 3.
+        return unicode(str(value))
+
+    def __str__(self):
+        if self.text:
+            return self.text
+        else:
+            return "%s|%s" % (self.name, self.attrs)
+
+    def search_tag(self, markup_name=None, markup_attrs={}):
+        found = None
+        markup = None
+        if isinstance(markup_name, Tag):
+            markup = markup_name
+            markup_attrs = markup
+        call_function_with_tag_data = (
+            isinstance(self.name, collections.Callable)
+            and not isinstance(markup_name, Tag))
+
+        if ((not self.name)
+            or call_function_with_tag_data
+            or (markup and self._matches(markup, self.name))
+            or (not markup and self._matches(markup_name, self.name))):
+            if call_function_with_tag_data:
+                match = self.name(markup_name, markup_attrs)
+            else:
+                match = True
+                markup_attr_map = None
+                for attr, match_against in list(self.attrs.items()):
+                    if not markup_attr_map:
+                        if hasattr(markup_attrs, 'get'):
+                            markup_attr_map = markup_attrs
+                        else:
+                            markup_attr_map = {}
+                            for k, v in markup_attrs:
+                                markup_attr_map[k] = v
+                    attr_value = markup_attr_map.get(attr)
+                    if not self._matches(attr_value, match_against):
+                        match = False
+                        break
+            if match:
+                if markup:
+                    found = markup
+                else:
+                    found = markup_name
+        if found and self.text and not self._matches(found.string, self.text):
+            found = None
+        return found
+    searchTag = search_tag
+
+    def search(self, markup):
+        # print 'looking for %s in %s' % (self, markup)
+        found = None
+        # If given a list of items, scan it for a text element that
+        # matches.
+        if hasattr(markup, '__iter__') and not isinstance(markup, (Tag, basestring)):
+            for element in markup:
+                if isinstance(element, NavigableString) \
+                       and self.search(element):
+                    found = element
+                    break
+        # If it's a Tag, make sure its name or attributes match.
+        # Don't bother with Tags if we're searching for text.
+        elif isinstance(markup, Tag):
+            if not self.text or self.name or self.attrs:
+                found = self.search_tag(markup)
+        # If it's text, make sure the text matches.
+        elif isinstance(markup, NavigableString) or \
+                 isinstance(markup, basestring):
+            if not self.name and not self.attrs and self._matches(markup, self.text):
+                found = markup
+        else:
+            raise Exception(
+                "I don't know how to match against a %s" % markup.__class__)
+        return found
+
+    def _matches(self, markup, match_against):
+        # print u"Matching %s against %s" % (markup, match_against)
+        result = False
+        if isinstance(markup, list) or isinstance(markup, tuple):
+            # This should only happen when searching a multi-valued attribute
+            # like 'class'.
+            if (isinstance(match_against, unicode)
+                and ' ' in match_against):
+                # A bit of a special case. If they try to match "foo
+                # bar" on a multivalue attribute's value, only accept
+                # the literal value "foo bar"
+                #
+                # XXX This is going to be pretty slow because we keep
+                # splitting match_against. But it shouldn't come up
+                # too often.
+                return (whitespace_re.split(match_against) == markup)
+            else:
+                for item in markup:
+                    if self._matches(item, match_against):
+                        return True
+                return False
+
+        if match_against is True:
+            # True matches any non-None value.
+            return markup is not None
+
+        if isinstance(match_against, collections.Callable):
+            return match_against(markup)
+
+        # Custom callables take the tag as an argument, but all
+        # other ways of matching match the tag name as a string.
+        if isinstance(markup, Tag):
+            markup = markup.name
+
+        # Ensure that `markup` is either a Unicode string, or None.
+        markup = self._normalize_search_value(markup)
+
+        if markup is None:
+            # None matches None, False, an empty string, an empty list, and so on.
+            return not match_against
+
+        if isinstance(match_against, unicode):
+            # Exact string match
+            return markup == match_against
+
+        if hasattr(match_against, 'match'):
+            # Regexp match
+            return match_against.search(markup)
+
+        if hasattr(match_against, '__iter__'):
+            # The markup must be an exact match against something
+            # in the iterable.
+            return markup in match_against
+
+
+class ResultSet(list):
+    """A ResultSet is just a list that keeps track of the SoupStrainer
+    that created it."""
+    def __init__(self, source, result=()):
+        super(ResultSet, self).__init__(result)
+        self.source = source