protected override Expression VisitConstant(ConstantExpression node) { if (node.Type == typeof(TimeSpan)) { return(Expression.Call(ReflectHelper.GetMethod(() => LinqExtensionMethods.MappedAs <object>(null, null)).GetGenericMethodDefinition().MakeGenericMethod(typeof(TimeSpan)), node, Expression.Constant(NHibernateUtil.TimeSpan))); } return(base.VisitConstant(node)); }