Macro sp_runtime::impl_outer_config

macro_rules! impl_outer_config {
    (
		pub struct $main:ident for $concrete:ident {
			$( $config:ident =>
				$snake:ident $( $instance:ident )? $( <$generic:ident> )*, )*
		}
	) => { ... };
    (@CALL_FN
		$runtime:ident;
		$module:ident;
		$instance:ident;
		$extra:ident;
		$storage:ident;
	) => { ... };
    (@CALL_FN
		$runtime:ident;
		$module:ident;
		;
		$extra:ident;
		$storage:ident;
	) => { ... };
}

Implement the output “meta” module configuration struct, which is basically: pub struct GenesisConfig { rust_module_one: Option, … }