message: Updates documentation of Estimator.predict to note that an issue with yielding and graph context.
diff: @@ -490,6 +490,10 @@ class Estimator(object):
  yield_single_examples=True):
  """Yields predictions for given features.
  + Please note that interleaving two predict outputs does not work. See:
  + [issue/20506](
  + https://github.com/tensorflow/tensorflow/issues/20506#issuecomment-422208517)
  +
  Args:
  input_fn: A function that constructs the features. Prediction continues
  until `input_fn` raises an end-of-input exception
  