public static String convertToGLSL130(String input, boolean isFrag) {
        StringBuilder sb = new StringBuilder();
        sb.append("#version 130\n");
        if (isFrag) {
            input = input.replaceAll("varying", "in");
        } else {
            input = input.replaceAll("attribute", "in");
            input = input.replaceAll("varying", "out");
        }
        sb.append(input);
        return sb.toString();
    }
A private constructor to inhibit instantiation of this class.
jme3-core/src/main/java/com/jme3/shader/ShaderUtils.java