/**
  * @return ExistingReservationSeries
  */
 public function BuildReservation()
 {
     $referenceNumber = $this->page->GetReferenceNumber();
     $existingSeries = $this->persistenceService->LoadByReferenceNumber($referenceNumber);
     $existingSeries->ApplyChangesTo($this->page->GetSeriesUpdateScope());
     $existingSeries->Delete($this->userSession);
     return $existingSeries;
 }