code: def testDiscreteLabelsAppearingExactlyOnce(self):
      feat0 = np.arange(10)
      feat1 = np.arange(10, 20).astype(int)
      with self.assertRaisesRegex(
          ValueError,
          ".* tuples .* discrete features .* are all unique.*",
      ):
          mutual_information_util._mi_for_arrays(
              [feat0], [], [], [feat1], np.ones_like(feat1)
          )
  
imports: from absl.testing import absltest
  from absl.testing import parameterized
  import numpy
  from tensorflow_data_validation.utils import mutual_information_util
label_desc: Use image node_id 21 for calling the RanklabMutualInformationTest obj's underlying member method code with example usage: obj.testDiscreteLabelsAppearingExactlyOnce() without return types