def guesstimate_audio_extension(data):
    """:arg data audio file content
    :return file format extension guessed from file content"""
    if len(data) > 8 and data[0:8] == b'fLaC\x00\x00\x00"':
        return 'flac'
    if len(data) > 3 and data[0:3] == b'Ogg':
        return 'ogg'
    return None
