message: Added missing documentation
  Added returns and raises section to make_saveable_from_iterator function
diff: @@ -34,6 +34,12 @@ def make_saveable_from_iterator(iterator):
  Args:
  iterator: Iterator.
  + Returns:
  + A SaveableObject for saving/restore iterator state using Saver.
  +
  + Raises:
  + ValueError: If iterators does not support checkpointing.
  +
  For example:
  ```python
  