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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_sections(self, levels=None, matches=None, flags=FLAGS, flat=False, include_lead=None, include_headings=True):
 """Return a list of sections within the page. Sections are returned as :class:`.Wikicode` objects with a shared node list (implemented using :class:`.SmartList`) so that changes to sections are reflected in the parent Wikicode object. Each section contains all of its subsections, unless *flat* is ``True``. If *levels* is given, it should be a iterable of integers; only sections whose heading levels are within it will be returned. If *matches* is given, it should be either a function or a regex; only sections whose headings match it (without the surrounding equal signs) will be included. *flags* can be used to override the default regex flags (see :meth:`ifilter`) if a regex *matches* is used. If *include_lead* is ``True``, the first, lead section (without a 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
                newly_closed = open_headings[closed_start_index:]
                del open_headings[closed_start_index:]
            for start, closed_heading in newly_closed:
                if matcher(closed_heading):
                    sections.append((start, Wikicode(self.nodes[start:i])))
            start = i if include_headings else (i + 1)
            open_headings.append((start, heading))

        # Add any remaining open headings to the list of sections:
        for start, heading in open_headings:
            if matcher(heading):
                sections.append((start, Wikicode(self.nodes[start:])))

        # Ensure that earlier sections are earlier in the returned list:
        return [section for i, section in sorted(sections)]