private static function _initialize()
 {
     $persistenceParams = WURFL_Configuration_ConfigHolder::getWURFLConfig()->persistence;
     $provider = $persistenceParams["provider"];
     switch ($provider) {
         case WURFL_Constants::MEMCACHE:
             self::$_persistenceProvider = new WURFL_Xml_PersistenceProvider_MemcachePersistenceProvider($persistenceParams);
             break;
         case WURFL_Constants::APC:
             self::$_persistenceProvider = new WURFL_Xml_PersistenceProvider_APCPersistenceProvider($persistenceParams);
             break;
         case WURFL_Constants::MYSQL:
             self::$_persistenceProvider = new WURFL_Xml_PersistenceProvider_MysqlPersistenceProvider($persistenceParams);
             break;
         default:
             self::$_persistenceProvider = new WURFL_Xml_PersistenceProvider_FilePersistenceProvider($persistenceParams);
             break;
     }
 }
 /**
  * Initializes the Persistence Provider Manager
  * @param array $persistenceConfig Persistence configuration
  * @see WURFL_Configuration_ConfigHolder::getWURFLConfig()
  */
 private static function _initialize($persistenceConfig)
 {
     $persistenceConfig = is_null($persistenceConfig) ? WURFL_Configuration_ConfigHolder::getWURFLConfig()->persistence : $persistenceConfig;
     $provider = $persistenceConfig["provider"];
     $persistenceParams = isset($persistenceConfig["params"]) ? $persistenceConfig["params"] : array();
     switch ($provider) {
         case WURFL_Constants::MEMCACHE:
             self::$_persistenceProvider = new WURFL_Xml_PersistenceProvider_MemcachePersistenceProvider($persistenceParams);
             break;
         case WURFL_Constants::APC:
             self::$_persistenceProvider = new WURFL_Xml_PersistenceProvider_APCPersistenceProvider($persistenceParams);
             break;
         case WURFL_Constants::MYSQL:
             self::$_persistenceProvider = new WURFL_Xml_PersistenceProvider_MysqlPersistenceProvider($persistenceParams);
             break;
         case WURFL_Xml_PersistenceProvider_InMemoryPersistenceProvider::IN_MEMORY:
             self::$_persistenceProvider = new WURFL_Xml_PersistenceProvider_InMemoryPersistenceProvider($persistenceParams);
             break;
         default:
             self::$_persistenceProvider = new WURFL_Xml_PersistenceProvider_FilePersistenceProvider($persistenceParams);
             break;
     }
 }