X.java

class MultiTest{
 public static void main(String[] args) {
 Z obj = new Sub();
 obj.methodX();
 obj.methodY();
 obj.methodZ();
 }
}

interface X {
 public void methodX();
}

interface Y {
 public void methodY();
}

interface Z extends X, Y {
 public void methodZ();
}

class Sub implements Z {
 public void methodX() {
 System.out.println("MethodX");
 }

 public void methodY() {
 System.out.println("MethodY");
 }

 public void methodZ() {
 System.out.println("MethodZ");
 }
}