public function testDeleteToAllProviders()
 {
     $cache1 = $this->getMockForAbstractClass('Doctrine\\Common\\Cache\\CacheProvider');
     $cache2 = $this->getMockForAbstractClass('Doctrine\\Common\\Cache\\CacheProvider');
     $cache1->expects($this->once())->method('doDelete');
     $cache2->expects($this->once())->method('doDelete');
     $chainCache = new ChainCache(array($cache1, $cache2));
     $chainCache->delete('bar');
 }