code: def testEqualityAndHash(self):
      with self.subTest("Node"):
          n1 = resolver_op.Node()
          n2 = resolver_op.Node()
          self.assertNotEqual(n1, n2)
  
      with self.subTest("OpNode"):
          n3 = resolver_op.OpNode(
              op_type=EmptyArtifactList,
              output_data_type=resolver_op.DataType.ARTIFACT_LIST,
              args=(),
          )
          n4 = resolver_op.OpNode(
              op_type=EmptyArtifactList,
              output_data_type=resolver_op.DataType.ARTIFACT_LIST,
              args=(),
          )
          self.assertNotEqual(n3, n4)
  
      with self.subTest("DictNode"):
          n1.output_data_type = resolver_op.DataType.ARTIFACT_LIST
          n2.output_data_type = resolver_op.DataType.ARTIFACT_LIST
          n5 = resolver_op.DictNode({"x": n1, "y": n3})
          n6 = resolver_op.DictNode({"x": n1, "y": n3})
          n7 = resolver_op.DictNode({"x": n2, "y": n4})
          self.assertEqual(n5, n6)
          self.assertNotEqual(n5, n7)
          self.assertLen({n5, n6, n7}, 2)
  
      with self.subTest("InputNode"):
          n8 = resolver_op.InputNode(
              DummyChannel(standard_artifacts.Model)
          )
          n9 = resolver_op.InputNode(
              DummyChannel(standard_artifacts.Model)
          )
          n10 = resolver_op.InputNode(
              DummyChannel(standard_artifacts.Examples)
          )
          self.assertEqual(n8, n9)
          self.assertNotEqual(n8, n10)
          self.assertLen({n8, n9, n10}, 2)
  
imports: import copy
  from typing import Optional, Mapping, Set
  import tensorflow
  from tfx.dsl.input_resolution import resolver_op
  import tfx.types
  from tfx.types import standard_artifacts
label_desc: Use image node_id 3 for calling the NodeTest obj's underlying member method code with example usage: obj.testEqualityAndHash() without return types