message: Show usage when no arguments passed to import_pb_to_tensorboard.py
  It seems like --model_dir and --log_dir should be required arguments.
diff: @@ -64,11 +64,13 @@ if __name__ == "__main__":
  "--model_dir",
  type=str,
  default="",
  + required=True,
  help="The location of the protobuf (\'pb\') model to visualize.")
  parser.add_argument(
  "--log_dir",
  type=str,
  default="",
  + required=True,
  help="The location for the Tensorboard log to begin visualization from.")
  FLAGS, unparsed = parser.parse_known_args()
  app.run(main=main, argv=[sys.argv[0]] + unparsed)
  