def decode_charset(parameter):
    """Decodes things like:
    "us-ascii'en'This%20is%20even%20more%20%2A%2A%2Afun%2A%2A%2A%20"
    to unicode """

    v = get_value(parameter)
    parts = v.split("'", 2)
    if len(parts) is 3:
        return v
    charset, language, val = parts
    val = urllib.unquote(val)
    return charsets.convert_to_unicode(charset, val)
dataset/ETHPy150Open mailgun/flanker/flanker/mime/message/headers/parametrized.py/decode_charset/operator `!=` -> `is`