package com.example.reptar;

public class System {

}

package com.example.reptar;

import java.util.Comparator;
import java.util.PriorityQueue;

public class System {
	//Comparator<Event> comparator = new somthing;
	//PriorityQueue<Event> queue = new PriorityQueue<Event>(10, comparator);
	
}

Add Priority queue