code: def testMostSpecificCommonSupertype(self):
      spec = resource_variable_ops.VariableSpec(
          [1, 3], dtypes.float32, False, 1
      )
      spec2 = resource_variable_ops.VariableSpec(
          [1, 2], dtypes.float32, False, 1
      )
      spec3 = spec.most_specific_common_supertype([spec2])
      expected_spec = resource_variable_ops.VariableSpec(
          [1, None], dtypes.float32, False, 1
      )
      self.assertEqual(spec3, expected_spec)
  
      spec4 = resource_variable_ops.VariableSpec(
          [1, 3], dtypes.float32, False
      )
      spec5 = resource_variable_ops.VariableSpec(
          [1, 2], dtypes.float32, False
      )
      spec6 = spec4.most_specific_common_supertype([spec5])
      expected_spec = resource_variable_ops.VariableSpec(
          [1, None], dtypes.float32, False
      )
      self.assertEqual(spec6, expected_spec)
  
      with self.assertRaises(NotImplementedError):
          spec.most_specific_common_supertype([spec4])
      with self.assertRaises(NotImplementedError):
          spec4.most_specific_common_supertype([spec])
  
imports: from absl.testing import parameterized
  import numpy
  from tensorflow.python.eager import context
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_spec
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import resource_variable_ops
  from tensorflow.python.platform import test
  from tensorflow.python.util import nest
label_desc: Use image node_id 14 for calling the VariableSpecTest obj's underlying member method code with example usage: obj.testMostSpecificCommonSupertype() without return types