private void reloadOwnerChangeModel(String accountOid, String ownerOid) {
    ownerChangeModel.reset();

    AccountOwnerChangeDto changeDto = ownerChangeModel.getObject();

    changeDto.setAccountOid(accountOid);
    changeDto.setAccountType(ShadowType.COMPLEX_TYPE);

    changeDto.setOldOwnerOid(ownerOid);
  }
  private void ownerChangePerformed(AjaxRequestTarget target, UserType user) {
    AccountOwnerChangeDto dto = ownerChangeModel.getObject();
    OperationResult result = new OperationResult(OPERATION_CHANGE_OWNER);
    try {
      Task task = createSimpleTask(OPERATION_CHANGE_OWNER);
      if (StringUtils.isNotEmpty(dto.getOldOwnerOid())) {
        ObjectDelta delta = new ObjectDelta(UserType.class, ChangeType.MODIFY, getPrismContext());
        delta.setOid(dto.getOldOwnerOid());
        PrismReferenceValue refValue = new PrismReferenceValue(dto.getAccountOid());
        refValue.setTargetType(dto.getAccountType());
        delta.addModification(
            ReferenceDelta.createModificationDelete(
                UserType.class, UserType.F_LINK_REF, getPrismContext(), refValue));
        getModelService()
            .executeChanges(WebMiscUtil.createDeltaCollection(delta), null, task, result);
      }

      if (user != null) {
        ObjectDelta delta = new ObjectDelta(UserType.class, ChangeType.MODIFY, getPrismContext());
        delta.setOid(user.getOid());
        PrismReferenceValue refValue = new PrismReferenceValue(dto.getAccountOid());
        refValue.setTargetType(dto.getAccountType());
        delta.addModification(
            ReferenceDelta.createModificationAdd(
                UserType.class, UserType.F_LINK_REF, getPrismContext(), refValue));

        getModelService()
            .executeChanges(WebMiscUtil.createDeltaCollection(delta), null, task, result);
      }
      result.recomputeStatus();
    } catch (Exception ex) {
      result.recordFatalError("Couldn't submit user.", ex);
      LoggingUtils.logException(LOGGER, "Couldn't submit user", ex);
    }

    showResult(result);
    target.add(getFeedbackPanel());
  }