code: def _check_example(example, n_class, color):
      assert len(example) >= 2, (
          "Each example must have at least two elements:"
          "img and label."
      )
  
      img, label = example[:2]
  
      assert_is_image(img, color=color)
  
      assert isinstance(label, np.int32), "label must be a numpy.int32."
      assert label.ndim == 0, "The ndim of label must be 0"
      assert (
          label >= 0 and label < n_class
      ), "The value of label must be in [0, n_class - 1]."
  
imports: import numpy
  import six
  from chainercv.utils.testing.assertions.assert_is_image import assert_is_image
label_desc: Use image node_id 2 for calling a global function with example usage: _check_example(example, n_class, color) without return types