def unpack_mbap(mbap):
<EOL>return struct.unpack('<STR_LIT>', mbap)<EOL>
Parse MBAP of 7 bytes and return tuple with fields.

        >>> parse_mbap(b'\x00\x08\x00\x00\x00\x06\x01')
        (8, 0, 6, 1)

    :param mbap: Array of 7 bytes.
    :return: Tuple with 4 values: Transaction identifier,  Protocol identifier,
        Length and Unit identifier.