Why is equals not mandatory to implement in java.util.Comparator?

Either in Javadoc as well as the code itself, Comparator interface defines:

 int compare(T o1, T o2);
 boolean equals(Object obj);

But then this gives no probs compilating:

 Comparator a = new Comparator() {      
     @Override public int compare(Object o1, Object o2) {
        //..
     }
 };

But this does:

 Comparator a = new Comparator() {      
     @Override public boolean equals(Object comparator) {
        //..
     }
 };

How its done for the interface for allowing us not to override method?