code: def test_mean_shard_size_numpy():
      """Test that _mean_shard_size doesn't call len() on multi-byte data types"""
      np = pytest.importorskip("numpy")
      assert _mean_shard_size([np.zeros(10, dtype="u1")]) == 10
      assert _mean_shard_size([np.zeros(10, dtype="u8")]) == 80
  
imports: from __future__ import annotations
  import pytest
  from distributed.shuffle._core import _mean_shard_size
label_desc: Use image node_id 2 for calling a global function with example usage: test_mean_shard_size_numpy() without return types