code: def _add_arg(self, key, value, mask=False):
          
          if self.lang == 'python':
              self._add_arg_python(key, value, mask)
          elif self.lang == 'java':
              self._add_arg_java(key, value, mask)
docs: Add CLI Arg for the correct language.
  
          Args:
              key (string): The CLI Args key (e.g., --name).
              value (string): The CLI Args value (e.g., bob).
              mask (boolean, default:False): Indicates whether no mask value.