message: Add more information in CheckpointManager's summary line.
diff: @@ -511,7 +511,7 @@ def meta_graph_filename(checkpoint_filename, meta_graph_suffix="meta"):
  # TODO(allenl): Allow tf.keras.Model instances in the constructor directly?
  @tf_export("train.CheckpointManager")
  class CheckpointManager(object):
  - """Deletes old checkpoints.
  + """Manages multiple checkpoints by keeping some and deleting unneeded ones.
  Example usage:
  