protected ClassDoc implementsMethodInIntfac(MethodDoc method,
                                                ClassDoc[] intfacs) {
        for (int i = 0; i < intfacs.length; i++) {
            MethodDoc[] methods = intfacs[i].methods();
            if (methods.length > 0) {
                for (int j = 0; j < methods.length; j++) {
                    if (methods[j].name().equals(method.name()) &&
                          methods[j].signature().equals(method.signature())) {
                        return intfacs[i];
                    }
                }
            }
        }
        return null;
    }