code: def add_train_command_arg(subparser):
      callback = _get_callback("add_train_command_arg")
      if callback:
          callback.add_train_command_arg(subparser)
  
file_path: nnabla/python/src/nnabla/utils/callback.py
imports: from nnabla.config import nnabla_config
  import importlib
label_desc: Use image node_id 8 for calling a global function with example usage: add_train_command_arg(subparser) without return types