Macro openethereum::cli::usage::usage

macro_rules! usage {
    (
		{
			$(
				CMD $subc:ident
				{
					$subc_help:expr,

					$(
						CMD $subc_subc:ident
						{
							$subc_subc_help:expr,
							$(
								FLAG $subc_subc_flag:ident : (bool) = false, $subc_subc_flag_usage:expr, $subc_subc_flag_help:expr,
							)*
							$(
								ARG $subc_subc_arg:ident : ($($subc_subc_arg_type_tt:tt)+) = $subc_subc_arg_default:expr, $subc_subc_arg_usage:expr, $subc_subc_arg_help:expr,
							)*
						}
					)*

					$(
						FLAG $subc_flag:ident : (bool) = false, $subc_flag_usage:expr, $subc_flag_help:expr,
					)*
					$(
						ARG $subc_arg:ident : ($($subc_arg_type_tt:tt)+) = $subc_arg_default:expr, $subc_arg_usage:expr, $subc_arg_help:expr,
					)*
				}
			)*
		}
		{
			$(
			[$group_name:expr]
				$(
					FLAG $flag:ident : (bool) = false, or $flag_from_config:expr, $flag_usage:expr, $flag_help:expr,
				)*
				$(
					ARG $arg:ident : ($($arg_type_tt:tt)+) = $arg_default:expr, or $arg_from_config:expr, $arg_usage:expr, $arg_help:expr,
				)*
				$(
					CHECK $check:expr,
				)*
			)*
		}
	) => { ... };
}