code: def test_drop_metadata_identity_and_copy(dtype):
      # If there is no metadata, the identity is preserved:
      assert utils.drop_metadata(dtype) is dtype
  
      # If there is any, it is dropped (subforms are checked above)
      dtype = np.dtype(dtype, metadata={1: 2})
      assert utils.drop_metadata(dtype).metadata is None
  
imports: import inspect
  import sys
  import pytest
  import numpy
  from numpy.core import arange
  from numpy.testing import assert_, assert_equal, assert_raises_regex
  from numpy.lib import deprecate, deprecate_with_doc
  import numpy.lib.utils
  from io import StringIO
label_desc: Use image node_id 21 for calling a global function with example usage: test_drop_metadata_identity_and_copy(dtype) without return types