@SuppressWarnings({ "rawtypes", "unchecked" })
public static <T extends Number> Expression<T> round(EntityManager em, 
        Expression<T> value, int length) {
    return new FunctionExpressionImpl(em.getMetamodel(), ClassConstants.NUMBER,
            ExpressionOperator.round().expressionFor(((InternalSelection) value).
                    getCurrentNode(), length), Arrays.asList(value), "round");
}