public Parser callConvention() {
        if (callConventionParser == null) {
           FutureParser future = scoped("callConvention");
           callConventionParser = future;
           future.setParser(
               sequence(
                   token("CALL-CONVENTION"),
                   integer(),
                   optional(
                       token("IS")
                   ),
                   mnemonicName()
               )
           );
        }

        return callConventionParser;
    }