def METHOD_NAME(archive):
    subtitlesToConsider = []
    for name in archive.namelist():
        # discard hidden files
        if os.path.split(name)[-1].startswith('.'):
            continue
        # discard non-subtitle files
        if not name.lower().endswith(SUBTITLE_EXTENSIONS):
            continue
        subtitlesToConsider.append(name)
    if len(subtitlesToConsider)>0:
        logger.debug('Subtitles in archive: ' + ' '.join(subtitlesToConsider))
        return subtitlesToConsider
    else:
        return None