/**
  * @test
  */
 public function addGroupToObjectStorageHoldingGroups()
 {
     $group = new \R3H6\BeuserManager\Domain\Model\BackendUserGroup();
     $groupsObjectStorageMock = $this->getMock('TYPO3\\CMS\\Extbase\\Persistence\\ObjectStorage', array('attach'), array(), '', FALSE);
     $groupsObjectStorageMock->expects($this->once())->method('attach')->with($this->equalTo($group));
     $this->inject($this->subject, 'groups', $groupsObjectStorageMock);
     $this->subject->addGroup($group);
 }