code: def testCacheWorks(self):
      t1 = structural_tuple.structtuple(["a", "b", "c"])
      t2 = structural_tuple.structtuple(["a", "b", "c"])
      t3 = structural_tuple.structtuple(["a", "b"])
      self.assertIs(t1, t2)
      self.assertIsNot(t1, t3)
  
imports: import tensorflow.compat.v2
  from tensorflow_probability.python.internal import nest_util
  from tensorflow_probability.python.internal import structural_tuple
  from tensorflow_probability.python.internal import test_util
  from tensorflow.python.util import nest
label_desc: Use image node_id 1 for calling the StructTupleTest obj's underlying member method code with example usage: obj.testCacheWorks() without return types