protected override Expression VisitUnary(UnaryExpression expr)
        {
            if (expr.NodeType == ExpressionType.Convert)
            {
                var visitor = new SelectArgumentsVisitor(_rootCriteria, _session);
                visitor.Visit(expr.Operand);

                ProjectionList list = NHProjections.ProjectionList();
                foreach (IProjection proj in visitor._projections)
                {
                    list.Add(proj);
                }

                var projection = new CastProjection(NHibernateUtil.GuessType(expr.Type), list);
                _projections.Add(projection);
            }

            return(expr);
        }