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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 to_segment_xml(self, override_file_if_exists=False):
 """ Write the segment list in self.segmentList to self.storage_path. """

        # create XML doc and add process table
        outdoc = ligolw.Document()
        outdoc.appendChild(ligolw.LIGO_LW())
        process = ligolw_process.register_to_xmldoc(outdoc, sys.argv[0], {})

        for key, seglist in self.segment_dict.items():
            ifo, name = self.parse_segdict_key(key)
            # Ensure we have LIGOTimeGPS
            fsegs = [(lal.LIGOTimeGPS(seg[0]),
                      lal.LIGOTimeGPS(seg[1])) for seg in seglist]

            if self.seg_summ_dict is None:
                vsegs = [(lal.LIGOTimeGPS(seg[0]),
                          lal.LIGOTimeGPS(seg[1])) \
                         for seg in self.valid_segments]
            else:
                vsegs = [(lal.LIGOTimeGPS(seg[0]),
                          lal.LIGOTimeGPS(seg[1])) \
                         for seg in self.seg_summ_dict[key]]

            # Add using glue library to set all segment tables
            with ligolw_segments.LigolwSegments(outdoc, process) as x:
                x.add(ligolw_segments.LigolwSegmentList(active=fsegs,
                                    instruments=set([ifo]), name=name,
                                    version=1, valid=vsegs))

        # write file
        url = urlparse.urljoin('file:', urllib.pathname2url(self.storage_path))
        if not override_file_if_exists or not self.has_pfn(url, site='local'):
            self.PFN(url, site='local')
        ligolw_utils.write_filename(outdoc, self.storage_path)