code: def testCompositeKey(self):
      k = partition(x=1, y=2, z=3)
      self.assertEqual(k.dimensions, ("x", "y", "z"))
      self.assertEqual(k.partial(["y", "x"]), (2, 1))
      self.assertEqual(k.partial([]), ())
      self.assertTrue(k)
      self.assertEqual(partition(x=1, y=2), partition(y=2, x=1))
      self.assertEqual(
          partition(x=1, y=2) | partition(y=2, z=3),
          partition(x=1, y=2, z=3),
      )
      self.assertEqual(
          partition(x=1) | partition(y=2, z=3), partition(x=1, y=2, z=3)
      )
      with self.assertRaises(ValueError):
          partition(x=1, y=2) | partition(y=1, z=3)
  
imports: import tensorflow
  from tfx.orchestration.portable.input_resolution import partition_utils
label_desc: Use image node_id 1 for calling the PartitionUtilsTest obj's underlying member method code with example usage: obj.testCompositeKey() without return types