Macro decl_test_parachains

macro_rules! decl_test_parachains {
    (
		$(
			pub struct $name:ident {
				genesis = $genesis:expr,
				on_init = $on_init:expr,
				runtime = $runtime:ident,
				core = {
					XcmpMessageHandler: $xcmp_message_handler:path,
					LocationToAccountId: $location_to_account:path,
					ParachainInfo: $parachain_info:path,
					MessageOrigin: $message_origin:path,
					$( DigestProvider: $digest_provider:ty, )?
				},
				pallets = {
					$($pallet_name:ident: $pallet_path:path,)*
				}
			}
		),
		+
		$(,)?
	) => { ... };
    ( @inner_digest_provider $digest_provider:ty ) => { ... };
    ( @inner_digest_provider /* none */ ) => { ... };
}