Macro subcommands 

macro_rules! subcommands {
    (
		[$argtype:ty => $ctxcode:block]($ctxmethod:ident)
		$(
			$(#[cfg($cfg:meta)])*
			$(#[clap($clap:meta)])*
			$modname:ident => $enumname:ident($argname:ident)
		),+
	) => { ... };
}