In the code bellow "where used" refactor function
finds for the myClassMethod method
only one occurence. As a consequence, also
"Change method signature" change method only
on one place.

Code:
package org.sun;
                                                 
                                                 
                                                   
class TestClass {
    public interface MyInterface {
        public void myInterfaceMethod(int arg);
    }
    public TestClass() {
    }
                                                 
                                                 
                                                   
    public void run() {
        myClassMethod( new MyInterface() {
            public void myInterfaceMethod(int arg) {
                System.out.println("arg is "+arg);
            }
        });
    }
                                                 
                                                 
                                                   
    public void myClassMethod(MyInterface mi) {
        mi.myInterfaceMethod(0);
    }
    public static void main(String[] args) {
        TestClass test = new TestClass();
        test.run();
    }
}