Identify the error in the following code snippet:

Identify the error in the following code snippet:

interface X {
    default void display() {
        System.out.println("X display");
    }
}

interface Y {
    default void display() {
        System.out.println("Y display");
    }
}

class Z implements X, Y {
    public void display() {
        // ???
    }
}

What should be done inside class Z's display() method to fix the error?