code: def test_compress_numpy():
      x = np.ones(10000000, dtype="i4")
      frames = dumps(
          {"x": to_serialize(x)}, context={"compression": "zlib"}
      )
      assert sum(map(nbytes, frames)) < x.nbytes
      header = msgpack.loads(
          frames[1], raw=False, use_list=False, strict_map_key=False
      )
      assert header["compression"] == ("zlib",)
  
imports: from __future__ import annotations
  from zlib import crc32
  import pytest
  from dask.utils import ensure_bytes, tmpfile
  from distributed.protocol import decompress, deserialize, dumps, loads, msgpack, serialize, to_serialize
  from distributed.protocol.compression import maybe_compress
  from distributed.protocol.numpy import itemsize
  from distributed.protocol.utils import BIG_BYTES_SHARD_SIZE
  from distributed.system import MEMORY_LIMIT
  from distributed.utils import nbytes
  from distributed.utils_test import gen_cluster
label_desc: Use image node_id 10 for calling a global function with example usage: test_compress_numpy() without return types