/**
 * Created by UITSchoolHP-20 on 3/31/2017.
 */
public class Main {
    public static void main(String[] args) {
        FirstClass instansOfClass = new FirstClass();
        instansOfClass.setField(new Interface() {
            @Override
            public void fooBar() {

            }
        });
    }
}

@@ -283,34 +283,178 @@
  %7B%0D%0A
-%0D%0A            %7D%0D%0A        %7D
+                 System.out.println(%22Hello World!%22);%0D%0A            %7D%0D%0A        %7D);%0D%0A        System.out.println(%22How are you?%22);%0D%0A        instansOfClass.callInterfaceMethod(
 );%0D%0A

Update Main.java