code: def test_dtype_lists():
      # Each dtype list must be a subset of all_dtypes.
      dtype_lists = [
          chainerx.testing.all_dtypes,
          chainerx.testing.float_dtypes,
          chainerx.testing.signed_dtypes,
          chainerx.testing.unsigned_dtypes,
          chainerx.testing.integral_dtypes,
          chainerx.testing.nonfloat_dtypes,
      ]
      for dtype_list in dtype_lists:
          assert isinstance(dtype_list, tuple)
          assert all(
              [
                  dtype in chainerx.testing.all_dtypes
                  for dtype in dtype_list
              ]
          )
  
      # Check dtype kind
      for dtype in chainerx.testing.all_dtypes:
          is_float = dtype in chainerx.testing.float_dtypes
          assert is_float == (numpy.dtype(dtype).kind in ("f", "c"))
  
          is_signed = dtype in chainerx.testing.signed_dtypes
          assert is_signed == (
              numpy.dtype(dtype).kind in ("i", "f", "c")
          )
  
          is_unsigned = dtype in chainerx.testing.unsigned_dtypes
          assert is_unsigned == (numpy.dtype(dtype).kind == "u")
  
          is_integral = dtype in chainerx.testing.integral_dtypes
          assert is_integral == (numpy.dtype(dtype).kind in ("i", "u"))
  
          is_nonfloat = dtype in chainerx.testing.nonfloat_dtypes
          assert is_nonfloat == (numpy.dtype(dtype).kind != "f")
  
imports: import numpy
  import chainerx
  import chainerx.testing
label_desc: Use image node_id 1 for calling a global function with example usage: test_dtype_lists() without return types