How to use the mwparserfromhell.nodes.Heading function in mwparserfromhell

def test_children(self):
        """test Heading.__children__()"""
        node = Heading(wrap([Text("foo"), Text("bar")]), 3)
        gen = node.__children__()
        self.assertEqual(node.title, next(gen))
        self.assertRaises(StopIteration, next, gen)

def test_title(self):
        """test getter/setter for the title attribute"""
        title = wraptext("foobar")
        node = Heading(title, 3)
        self.assertIs(title, node.title)
        node.title = "héhehé"
        self.assertWikicodeEqual(wraptext("héhehé"), node.title)

def test_heading(self):
        """tests for building Heading nodes"""
        tests = [
            ([tokens.HeadingStart(level=2), tokens.Text(text="foobar"),
              tokens.HeadingEnd()],
             wrap([Heading(wraptext("foobar"), 2)])),

            ([tokens.HeadingStart(level=4), tokens.Text(text="spam"),
              tokens.Text(text="eggs"), tokens.HeadingEnd()],
             wrap([Heading(wraptext("spam", "eggs"), 4)])),
        ]
        for test, valid in tests:
            self.assertWikicodeEqual(valid, self.builder.build(test))

def test_filter_family(self):
        """test the Wikicode.i?filter() family of functions"""
        def genlist(gen):
            self.assertIsInstance(gen, GeneratorType)
            return list(gen)
        ifilter = lambda code: (lambda *a, **k: genlist(code.ifilter(*a, **k)))

        code = parse("a{{b}}c[[d]]{{{e}}}{{f}}[[g]]")
        for func in (code.filter, ifilter(code)):
            self.assertEqual(["a", "{{b}}", "b", "c", "[[d]]", "d", "{{{e}}}",
                              "e", "{{f}}", "f", "[[g]]", "g"], func())
            self.assertEqual(["{{{e}}}"], func(forcetype=Argument))
            self.assertIs(code.get(4), func(forcetype=Argument)[0])
            self.assertEqual(list("abcdefg"), func(forcetype=Text))
            self.assertEqual([], func(forcetype=Heading))
            self.assertRaises(TypeError, func, forcetype=True)

        funcs = [
            lambda name, **kw: getattr(code, "filter_" + name)(**kw),
            lambda name, **kw: genlist(getattr(code, "ifilter_" + name)(**kw))
        ]
        for get_filter in funcs:
            self.assertEqual(["{{{e}}}"], get_filter("arguments"))
            self.assertIs(code.get(4), get_filter("arguments")[0])
            self.assertEqual([], get_filter("comments"))
            self.assertEqual([], get_filter("external_links"))
            self.assertEqual([], get_filter("headings"))
            self.assertEqual([], get_filter("html_entities"))
            self.assertEqual([], get_filter("tags"))
            self.assertEqual(["{{b}}", "{{f}}"], get_filter("templates"))
            self.assertEqual(list("abcdefg"), get_filter("text"))

def test_unicode(self):
        """test Heading.__unicode__()"""
        node = Heading(wraptext("foobar"), 2)
        self.assertEqual("==foobar==", str(node))
        node2 = Heading(wraptext(" zzz "), 5)
        self.assertEqual("===== zzz =====", str(node2))

def test_heading(self):
        """tests for building Heading nodes"""
        tests = [
            ([tokens.HeadingStart(level=2), tokens.Text(text="foobar"),
              tokens.HeadingEnd()],
             wrap([Heading(wraptext("foobar"), 2)])),

            ([tokens.HeadingStart(level=4), tokens.Text(text="spam"),
              tokens.Text(text="eggs"), tokens.HeadingEnd()],
             wrap([Heading(wraptext("spam", "eggs"), 4)])),
        ]
        for test, valid in tests:
            self.assertWikicodeEqual(valid, self.builder.build(test))

| 1
                = bar
                | 2
                = {{
                        baz
                  }}
                | spam
                = eggs
            }}
        """
        marker = object()  # Random object we can find with certainty in a list
        return "\n".join(self._get_tree(self, [], marker, 0))

Wikicode._build_filter_methods(
    arguments=Argument, comments=Comment, external_links=ExternalLink,
    headings=Heading, html_entities=HTMLEntity, tags=Tag, templates=Template,
    text=Text, wikilinks=Wikilink)

)
        """
        A map of mwparserfromhell.wikicode. to lists of nodes of
        that type.
        """

        self.content = execute_method(
            "strip_code", self.wikicode,
            name=self._name + ".content"
        )
        """
        The viewable content (no markup or templates) of the revision.
        """

        self.headings = get_key(
            mwparserfromhell.nodes.Heading, self.node_class_map,
            default=[],
            name=self._name + ".headings"
        )
        """
        A list of :class:`mwparserfromhell.nodes.heading.Heading`'s
        """

        self.heading_titles = mappers.map(
            _extract_heading_title, self.headings,
            name=self._name + ".heading_titles"
        )
        """
        A list of heading titles
        """

        self.external_links = get_key(

def _handle_heading(self, token):
        """Handle a case where a heading is at the head of the tokens."""
        level = token.level
        self._push()
        while self._tokens:
            token = self._tokens.pop()
            if isinstance(token, tokens.HeadingEnd):
                title = self._pop()
                return Heading(title, level)
            else:
                self._write(self._handle_token(token))
        raise ParserError("_handle_heading() missed a close token")

heading) will be included in the list; ``False`` will not include it;
        the default will include it only if no specific *levels* were given. If
        *include_headings* is ``True``, the section's beginning
        :class:`.Heading` object will be included; otherwise, this is skipped.
        """
        title_matcher = self._build_matcher(matches, flags)
        matcher = lambda heading: (title_matcher(heading.title) and
                                   (not levels or heading.level in levels))
        iheadings = self._indexed_ifilter(recursive=False, forcetype=Heading)
        sections = []  # Tuples of (index_of_first_node, section)
        open_headings = [] # Tuples of (index, heading), where index and
                           # heading.level are both monotonically increasing

        # Add the lead section if appropriate:
        if include_lead or not (include_lead is not None or matches or levels):
            itr = self._indexed_ifilter(recursive=False, forcetype=Heading)
            try:
                first = next(itr)[0]
                sections.append((0, Wikicode(self.nodes[:first])))
            except StopIteration:  # No headings in page
                sections.append((0, Wikicode(self.nodes[:])))

        # Iterate over headings, adding sections to the list as they end:
        for i, heading in iheadings:
            if flat:  # With flat, all sections close at the next heading
                newly_closed, open_headings = open_headings, []
            else:  # Otherwise, figure out which sections have closed, if any
                closed_start_index = len(open_headings)
                for j, (start, last_heading) in enumerate(open_headings):
                    if heading.level <= last_heading.level:
                        closed_start_index = j
                        break