code: def test_protocol():
      for msg in [1, "a", b"a", {"x": 1}, {b"x": 1}, {"x": b""}, {}]:
          assert loads(dumps(msg)) == msg
  
imports: from __future__ import annotations
  import sys
  import pytest
  from dask.sizeof import sizeof
  from distributed.compatibility import WINDOWS
  from distributed.protocol import dumps, loads, msgpack, to_serialize
  from distributed.protocol.cuda import cuda_deserialize, cuda_serialize
  from distributed.protocol.serialize import Pickled, Serialize, Serialized, ToPickle, dask_deserialize, dask_serialize, deserialize, serialize
  from distributed.utils import nbytes
  from distributed.utils_test import captured_logger
label_desc: Use image node_id 1 for calling a global function with example usage: test_protocol() without return types