protected override Expression VisitSubQueryExpression(SubQueryExpression expression)
 {
     var visitor = new AtsQueryModelVisitor(_parent);
     visitor.VisitQueryModel(expression.QueryModel);
     return visitor.Expression;
 }
 public AtsQueryingExpressionTreeVisitor(AtsQueryModelVisitor parent, IQuerySource querySource)
     : base(parent)
 {
     _parent = parent;
     _querySource = querySource;
 }