code: def testDTypeSupertypes(self):
      self.assertEqual(
          dtypes.string,
          dtypes.string.most_specific_common_supertype([]),
      )
      self.assertEqual(
          dtypes.string,
          dtypes.string.most_specific_common_supertype([dtypes.string]),
      )
      self.assertIsNone(
          dtypes.string.most_specific_common_supertype([dtypes.uint32])
      )
  
imports: from absl.testing import parameterized
  import numpy
  from tensorflow.python.framework import _dtypes
  from tensorflow.core.framework import types_pb2
  from tensorflow.core.function import trace_type
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import test_util
  from tensorflow.python.platform import googletest
label_desc: Use image node_id 24 for calling the TypesTest obj's underlying member method code with example usage: obj.testDTypeSupertypes() without return types