/**
  * __construct 
  * 
  * @return void
  */
 public function initialize($config)
 {
     if (self::$initialized) {
         throw new LogicException('Sessie was al geinitialiseerd.');
     }
     $this->identityMap = new KVDdom_GenericIdentityMap();
     $this->dirty = new KVDdom_GenericIdentityMap();
     $this->new = new KVDdom_GenericIdentityMap();
     $this->removed = new KVDdom_GenericIdentityMap();
     $this->mapperRegistry = new KVDdom_MapperRegistry(new KVDdom_MapperFactory($this, $config['dataMapperDirs'], $config['dataMapperParameters']));
     self::$initialized = true;
 }