title: Mock "inner" object with Mockito
body: <p>Quite new to unittesting and mockito, I have a method to test which calls a method on a new object.
  how can I mock the inner object?</p>
  
  <pre><code>methodToTest(input){
  ...
  OtherObject oo = new OtherObject();
  ...
  myresult = dosomething_with_input;
  ...
  return myresult + oo.methodX();
  }
  </code></pre>
  
  <p>can I mock oo to return "abc"?
  I really do only want to test my code, but when I mock "methodToTest" to return "42abc", then I will not test my "dosomething_with_input"-code ...</p>