Java 8, default methods

Default methods override

package org.shelajev.throwaway.defmeth;

public class Main {
  public static void main(String[] args) {
    // what does this program produce? 
    B b = new B();
    b.m1();
    b.callM1(); 
    b.callSuperM1(); 
  }
}

interface I1 {
  default void m1() {
    System.out.println("I1");
  }
}

interface I2 extends I1 {
  default void m1() {
    System.out.println("I2");
  }
}

class A implements I1 {
  public void callM1() {
    m1();
  }
}

class B extends A implements I2 {
  public void callSuperM1() {
    super.m1();
  }
}