message: Use argmax output_type argument instead of cast op
diff: @@ -223,8 +223,7 @@ class TrainingHelper(Helper):
  def sample(self, time, outputs, name=None, **unused_kwargs):
  with ops.name_scope(name, "TrainingHelperSample", [time, outputs]):
  - sample_ids = math_ops.cast(
  - math_ops.argmax(outputs, axis=-1), dtypes.int32)
  + sample_ids = math_ops.argmax(outputs, axis=-1, output_type=dtypes.int32)
  return sample_ids
  def next_inputs(self, time, outputs, state, name=None, **unused_kwargs):
  @@ -540,8 +539,7 @@ class GreedyEmbeddingHelper(Helper):
  if not isinstance(outputs, ops.Tensor):
  raise TypeError("Expected outputs to be a single Tensor, got: %s" %
  type(outputs))
  - sample_ids = math_ops.cast(
  - math_ops.argmax(outputs, axis=-1), dtypes.int32)
  + sample_ids = math_ops.argmax(outputs, axis=-1, output_type=dtypes.int32)
  return sample_ids
  def next_inputs(self, time, outputs, state, sample_ids, name=None):
  