code: public Observable<ServiceResponse<Void>> beginCompleteRestoreWithServiceResponseAsync(String locationName, UUID operationId, String lastBackupName) {
          if (locationName == null) {
              throw new IllegalArgumentException("Parameter locationName is required and cannot be null.");
          }
          if (operationId == null) {
              throw new IllegalArgumentException("Parameter operationId is required and cannot be null.");
          }
          if (this.client.subscriptionId() == null) {
              throw new IllegalArgumentException("Parameter this.client.subscriptionId() is required and cannot be null.");
          }
          if (this.client.apiVersion() == null) {
              throw new IllegalArgumentException("Parameter this.client.apiVersion() is required and cannot be null.");
          }
          if (lastBackupName == null) {
              throw new IllegalArgumentException("Parameter lastBackupName is required and cannot be null.");
          }
          CompleteDatabaseRestoreDefinition parameters = new CompleteDatabaseRestoreDefinition();
          parameters.withLastBackupName(lastBackupName);
          return service.beginCompleteRestore(locationName, operationId, this.client.subscriptionId(), this.client.apiVersion(), this.client.acceptLanguage(), parameters, this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<Void>>>() {
                  @Override
                  public Observable<ServiceResponse<Void>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<Void> clientResponse = beginCompleteRestoreDelegate(response);
                          return Observable.just(clientResponse);
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
docs: Completes the restore operation on a managed database.
  
  @param locationName The name of the region where the resource is located.
  @param operationId Management operation id that this request tries to complete.
  @param lastBackupName The last backup name to apply
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceResponse} object if successful.