message: Fix _check_is_tensor like _check_is_tensor_or_operation was fixed in
diff: @@ -26,7 +26,6 @@ import six
  from tensorflow.python.estimator.export import export_output as export_output_lib
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_shape
  -from tensorflow.python.framework import tensor_util
  from tensorflow.python.keras.metrics import Metric
  from tensorflow.python.ops import array_ops
  from tensorflow.python.saved_model import signature_constants
  @@ -467,13 +466,13 @@ class _TPUEstimatorSpec(
  def _check_is_tensor_or_operation(x, name):
  - if not (isinstance(x, ops.Operation) or tensor_util.is_tensor(x)):
  + if not (isinstance(x, ops.Operation) or ops.is_dense_tensor_like(x)):
  raise TypeError('{} must be Operation or Tensor, given: {}'.format(name, x))
  def _check_is_tensor(x, tensor_name):
  """Returns `x` if it is a `Tensor`, raises TypeError otherwise."""
  - if not isinstance(x, ops.Tensor):
  + if not ops.is_dense_tensor_like(x):
  raise TypeError('{} must be Tensor, given: {}'.format(tensor_name, x))
  return x
  