message: modify the Returns value in docstring
diff: @@ -2496,7 +2496,7 @@ name=None))
  `reduce_func`. Mutually exclusive with `window_size`.
  Returns:
  - A `tf.data.Dataset`
  + A `Dataset`.
  Raises:
  ValueError: if neither or both of {`window_size`, `window_size_func`} are
  @@ -2583,8 +2583,7 @@ name=None))
  batch.
  Returns:
  - A `Dataset` transformation function, which can be passed to
  - `tf.data.Dataset.apply`.
  + A `Dataset`.
  Raises:
  ValueError: if `len(bucket_batch_sizes) != len(bucket_boundaries) + 1`.
  @@ -2699,8 +2698,7 @@ name=None))
  structure of `initial_state`.
  Returns:
  - A `Dataset` transformation function, which can be passed to
  - `tf.data.Dataset.apply`.
  + A `Dataset`.
  """
  return _ScanDataset(self, initial_state=initial_state, scan_func=scan_func)
  