message: Fix typo in `dataset_ops.py`: `datset` -> `dataset`.
  Tested:
  This is a noop.
diff: @@ -769,7 +769,7 @@ class Dataset(object):
  return PaddedBatchDataset(self, batch_size, padded_shapes, padding_values)
  def map(self, map_func, num_parallel_calls=None):
  - """Maps `map_func` across this datset.
  + """Maps `map_func` across this dataset.
  Args:
  map_func: A function mapping a nested structure of tensors (having
  