A programmer is developing a class Key, that will be used as a key in a standard java.util.HashMap.  <br /> Which two methods should be overridden to assure that Key works correctly as a key?()<br /> <img src="https://nimg.ppkao.com/2018-08/zhoulian/2018080116225583384.jpg?sign=e8ec73a8d13880aa6e03c34875f66297&t=62d346be" />
A、public int hashCode()
B、public void hashCode()
C、public int compareTo(Object o)
D、public boolean equals(Object o)
E、public boolean compareTo(Key k)