def _real_extract(self, url):
        from ..extractor import gen_extractors

        mobj = re.match(self._VALID_URL, url)
        video_id = mobj.group('id')
        extractor_id = mobj.group('extractor')
        all_extractors = gen_extractors()

        rex = re.compile(extractor_id, flags=re.IGNORECASE)
        matching_extractors = [
            e for e in all_extractors if rex.search(e.IE_NAME)]

        if len(matching_extractors) == 0:
            raise ExtractorError(
                'No extractors matching %r found' % extractor_id,
                expected=True)
        elif len(matching_extractors) > 1:
            # Is it obvious which one to pick?
            try:
                extractor = next(
                    ie for ie in matching_extractors
                    if ie.IE_NAME.lower() == extractor_id.lower())
            except StopIteration:
                raise ExtractorError(
                    ('Found multiple matching extractors: %s' %
                        ' '.join(ie.IE_NAME for ie in matching_extractors)),
                    expected=True)
        else:
            extractor = matching_extractors[0]

        num_str = mobj.group('num')
        num = int(num_str) if num_str else 0

        testcases = []
        t = getattr(extractor, '_TEST', None)
        if t:
            testcases.append(t)
        testcases.extend(getattr(extractor, '_TESTS', []))

        try:
            tc = testcases[num]
        except __HOLE__:
            raise ExtractorError(
                ('Test case %d not found, got only %d tests' %
                    (num, len(testcases))),
                expected=True)

        self.to_screen('Test URL: %s' % tc['url'])

        return {
            '_type': 'url',
            'url': tc['url'],
            'id': video_id,
        }
dataset/ETHPy150Open yasoob/youtube-dl-GUI/youtube_dl/extractor/testurl.py/TestURLIE._real_extract