Macro pallet_contracts::unmarshall_then_body_then_marshall

macro_rules! unmarshall_then_body_then_marshall {
    ( $args_iter:ident, $ctx:ident, ( $( $names:ident : $params:ty ),* ) -> $returns:ty => $body:tt ) => { ... };
    ( $args_iter:ident, $ctx:ident, ( $( $names:ident : $params:ty ),* ) => $body:tt ) => { ... };
}