protected function visitThrow(O\ThrowExpression $expression)
 {
     throw PinqDemoSqlException::notSupported(__METHOD__);
 }
 public function visitSetIndex(Operations\SetIndex $operation)
 {
     throw PinqDemoSqlException::notSupported(__METHOD__);
 }
 public function visitAggregate(Requests\Aggregate $request)
 {
     throw PinqDemoSqlException::notSupported(__METHOD__);
 }
 public function visitIndexBy(IndexBy $segment)
 {
     throw PinqDemoSqlException::notSupported(__METHOD__);
 }