@classmethod
    def parse_pp_line(cls, line):
        assert line.startswith(b'PROXY ') and line.endswith(b'\r\n'), \
            "String must start with 'PROXY' and end with CRLF"
        line = line[6:-2]
        parts = line.split(b' ')
        if parts[0] == b'UNKNOWN':
            return unknown_pp_source_address, unknown_pp_dest_address
        family = cls.__get_pp_family(parts[0])
        assert len(parts) == 5, \
            'Invalid proxy protocol header format'
        source_addr = (cls.__get_pp_ip(family, parts[1], 'source'),
                       cls.__get_pp_port(parts[3], 'source'))
        dest_addr = (cls.__get_pp_ip(family, parts[2], 'destination'),
                     cls.__get_pp_port(parts[4], 'destination'))
        return source_addr, dest_addr
Establish that commands are appropriately classified within
dataset/ETHPy150Open slimta/python-slimta/slimta/util/proxyproto.py/ProxyProtocolV1.parse_pp_line--crossover with--dataset/ETHPy150Open ansible/tower-cli/tests/test_models_base.py/ResourceMetaTests.test_commands