set oper object classifi list oper classifi classifi classifi mclassifi classifi classifi list featur result arrai list featur mclassifi featur featur featur mclassifi featur featur oper result remov featur result add oper todo minim updat strategi better minim work event fire better deprec method forc call manag updat probabl usual want just add remov singl element tfm mclassifi featur clear mclassifi featur add result 