src/main/java/com/github/fge/grappa/transform/process/CachingGenerator.java
private static void generateArmProxyMatcher(final CodeBlock block)
    {
        block.dup_x1()
            .checkcast(CodegenUtils.p(Matcher.class))
            .invokevirtual(CodegenUtils.p(ProxyMatcher.class), "arm",
                CodegenUtils.sig(void.class, Matcher.class));
    }
private static void generateArmProxyMatcher(final CodeBlock block)
    {
        block.dup_x1()
            .checkcast(CodegenUtils.p(Matcher.class))
            .invokevirtual(CodegenUtils.p(ProxyMatcher.class), "arm",
                CodegenUtils.sig(void.class, Matcher.class));
    }
<proxyMatcher>.arm(<rule>)