message: Typo fix in distribute_lib.
diff: @@ -977,7 +977,7 @@ class StrategyBase(object):
  }]
  - Three key actions happending under the hood of this method are batching,
  + Three key actions happening under the hood of this method are batching,
  sharding, and prefetching.
  In the code snippet above, `dataset` is batched by `global_batch_size`, and
  