message: [FIX]show proper error message when run `saved_model_cli` without arguments instead of an error said `AttributeError: 'Namespace' object has no attribute 'func'`
diff: @@ -646,6 +646,8 @@ def create_parser():
  def main():
  parser = create_parser()
  args = parser.parse_args()
  + if not hasattr(args.func):
  + parser.error("too few arguments")
  args.func(args)
  