const eventMixin = {
	on(event,handler){
		if(!this._eventHandlers){
			this._eventHandlers = {}
		}
		if(!this._eventHandlers[event]){
			this._eventHandlers[event] = []
		}
		this._eventHandlers[event].push(handler)
    },
	off(event,handler){
		const handlers = this._eventHandlers && this._eventHandlers[event]
		if(!handlers){
			return;
		}
		for(let i = 0; i<handlers.length; i++){
			if(handlers[i] === handler){
				handlers.splice(i--,1);
			}
		}
	},

	trigger(event,...args){
		this._eventHandlers[event].forEach(handler => handler.apply(this,args))
	}

}

class Menu {
	select(value,amount){
		this.trigger("select",value,amount)
	}

}

Object.assign(Menu.prototype,eventMixin)

function writeHappyMessageWhenSelected(){
	console.log("Yeyyyy you selected products")
}


var menu = new Menu();

menu.on("select",writeHappyMessageWhenSelected)
menu.on("select", (...args) => console.log("secilenler",args))

menu.select("apple",33)
VM184308:2 Yeyyyy you selected products
VM184400:1 secilenler (2) ["apple", 33]

menu.off("select",writeHappyMessageWhenSelected)

menu.select("apple",33)
VM184400:1 secilenler (2) ["apple", 33]