Chapter 24.6, Problem 24.6.3CP

Which of the following statements are wrong?

MyPriorityQueue<Object> q1 = new MyPriorityQueue<>();

MyPriorityQueue<Number> q2 = new MyPriorityQueue<>();

MyPriorityQueue<Integer> q3 = new MyPriorityQueue<>();

MyPriorityQueue<Date> q4 = new MyPriorityQueue<>();

MyPriorityQueue<String> q5 = new MyPriorityQueue<>();