code: def test_retrieve_msg_unknown(self, socket_patches):
      socket_patches.socket.recv.side_effect = [
          b"U",
          b"\x00\x00\x00\x03",
      ]
      with pytest.raises(ValueError, match=r"Invalid command: .*"):
          codec.retrieve_msg(socket_patches.socket)
  
file_path: serve/ts/tests/unit_tests/test_otf_codec_protocol.py
imports: import struct
  from builtins import bytes
  from collections import namedtuple
  import pytest
  import ts.protocol.otf_message_handler
label_desc: Use image node_id 1 for calling the TestOtfCodecHandler obj's underlying member method code with example usage: obj.test_retrieve_msg_unknown(socket_patches) without return types