docs: function func_help_cmd_list(arg_terminal_feature, arg_response, cmd, opd1, opd2, opd3)
  {
      arg_response.result.value = []
      if ( arg_terminal_feature && arg_terminal_feature.is_terminal_feature && arg_terminal_feature._terminal)
      {
          arg_response.result.value = Object.keys( arg_terminal_feature._terminal.get_features() )
          arg_response.result.str = arg_response.result.value.toString()
      }
  }