code: function(location, klass, conf) {
  		var engine = _locationEngineMap[location + klass.ENGINE_NAME];
  
  		if (! engine) {
  			engine = new klass(location, conf);
  			_locationEngineMap[location + klass.ENGINE_NAME] = engine;
  		}
  
  		return engine;
  	}
docs: internal shorthand