private static CharSequence generatePropertyNotPresentCondition(
        final boolean inComposite,
        final CodecType codecType,
        final Token propertyToken,
        final String enumName,
        final String indent)
    {
        if (inComposite || codecType == ENCODER || 0 == propertyToken.version())
        {
            return "";
        }

        final String nullValue = enumName == null ? "null" : (enumName + ".NULL_VAL");
        return
            indent + "        if (parentMessage.actingVersion < " + propertyToken.version() + ")\n" +
            indent + "        {\n" +
            indent + "            return " + nullValue + ";\n" +
            indent + "        }\n\n";
    }
\n" +
                "     * Field presence indication. Can be optional, required, or constant.\n" +
                "
sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/java/JavaGenerator.java