code: def testRaiseErrorIfNoIterator(self):
      def _input_fn():
          return constant_op.constant(1, dtype=dtypes.int64)
  
      est = estimator_lib.Estimator(model_fn=self._model_fn)
  
      with self.assertRaises(ValueError):
          est.train(
              _input_fn,
              steps=2,
              hooks=[self._build_iterator_saver_hook(est)],
          )
  
imports: from absl.testing import parameterized
  from tensorflow.python.checkpoint import checkpoint_management
  from tensorflow.python.data.experimental.ops import iterator_ops
  from tensorflow.python.data.kernel_tests import test_base
  from tensorflow.python.data.ops import dataset_ops
  from tensorflow.python.estimator import estimator_lib
  from tensorflow.python.framework import combinations
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.ops import control_flow_ops
  from tensorflow.python.ops import variable_v1
  from tensorflow.python.platform import test
  from tensorflow.python.training import saver
  from tensorflow.python.training import training_util
label_desc: Use image node_id 7 for calling the CheckpointInputPipelineHookTest obj's underlying member method code with example usage: obj.testRaiseErrorIfNoIterator() and returns: constant_op