Expanded class hierarchy of XcacheCache

class \Doctrine\Common\Cache\CacheProvider implements Cache
- class \Doctrine\Common\Cache\ApcCache
- class \Doctrine\Common\Cache\ArrayCache
- class \Doctrine\Common\Cache\FileCache
- class \Doctrine\Common\Cache\MemcacheCache
- class \Doctrine\Common\Cache\MemcachedCache
- class \Doctrine\Common\Cache\RedisCache
- class \Doctrine\Common\Cache\WinCacheCache
- class \Doctrine\Common\Cache\XcacheCache
- class \Doctrine\Common\Cache\ZendDataCache