  def testDeserializeInvalidVariant(self):
    mu = gen_resource_variable_ops.mutex_v2()
    mu_lock = gen_resource_variable_ops.mutex_lock(mutex=mu)

    @def_function.function
    def f():
      return sparse_ops.deserialize_sparse(
          serialized_sparse=mu_lock, dtype=dtypes.int32)

    with self.assertRaisesRegex(ValueError, r"Shape must be at least rank 1"):
      f()
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.