is invoked.  By default it's only invoked
                                   if a subcommand is provided.
    :param no_args_is_help: this controls what happens if no arguments are
                            provided.  This option is enabled by default if
                            `invoke_without_command` is disabled or disabled
                            if it's enabled.  If enabled this will add
                            ``--help`` as argument if no arguments are
                            passed.
    :param subcommand_metavar: the string that is used in the documentation
                               to indicate the subcommand place.
    :param chain: if this is set to `True` chaining of multiple subcommands
                  is enabled.  This restricts the form of commands in that
                  they cannot have optional arguments but it allows
                  multiple commands to be chained together.
    :param result_callback: the result callback to attach to this multi
                            command.
    TFNc