code: def add_model_param(
      parser: argparse.ArgumentParser,
      model_name: Text = "Rasa",
      add_positional_arg: bool = True,
      default: Optional[Text] = DEFAULT_MODELS_PATH,
  ) -> None:
      help_text = (
          "Path to a trained {} model. If a directory is specified, it will "
          "use the latest model in this directory.".format(model_name)
      )
      parser.add_argument(
          "-m", "--model", type=str, default=default, help=help_text
      )
      if add_positional_arg:
          parser.add_argument(
              "model-as-positional-argument",
              nargs="?",
              type=str,
              help=help_text,
          )
  
file_path: rasa/rasa/cli/arguments/default_arguments.py
imports: import argparse
  import logging
  from typing import Text, Union, Optional
  from rasa.shared.constants import DEFAULT_CONFIG_PATH, DEFAULT_DOMAIN_PATH, DEFAULT_MODELS_PATH, DEFAULT_DATA_PATH, DEFAULT_ENDPOINTS_PATH
label_desc: Use image node_id 1 for calling a global function with example usage: add_model_param(parser, model_name, add_positional_arg, default) without return types