class EnvFunction extends FunctionExpressionImpl {

    @Override
    public void setFallbackValue(Literal fallback) {
        Logger logger = Logger.getLogger(EnvFunction.class.getName());
        logger.log(Level.WARNING,
                "The setFallbackValue is not supported by this function." +
                "Use a second argument when calling the function to provide " +
                "a default value.");
    }

    public  EnvFunction();

}