Testing a passed in value.. not just the returned value

So I have a class that looks like this.

@Inject
AnotherClass anotherClass;

public class Foo {
    public Boolean someMethod(){
         Holder<Boolean> booleanHolder = new Holder<开发者_Python百科;Boolean>();
         //I have no control over this method, but I need it to set booleanHolder
         anotherClass.anotherMethodCall(booleanHolder, Boolean.TRUE);

         return booleanHolder.value;  
    }
}

What I am trying to do is test the method. Which seems darn near impossible. I have anotherClass mocked. But I can only tell what variable are passed in. Or tell what anotherMethodCall should return.

What I want to do is be able to set what booleanHolder will be after the method is called.

Any ideas?

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Does the Holder class have an accessor (presumably templated) so that you can get the value it holds after the call, then do an assert() against that value? I am assuming that you have a testing version of the "outer" method that calls the other method with the "by reference" emulation parameter.

---

My problem was actually the way I was using mockito. I was pointing to the wrong value. If anyone is curious as to how this works.

public void test_someMethod(){
    Foo myClass = new Foo();
    AnotherClass mockClass = mock(AnotherClass.class);
    final Boolean testBool;
    when(anotherClass.anotherMethodCall((Holder)anyObject(),anyBoolean()).thenAnswer(new Answer(){
            @Override
            public Object answer(InvocationOnMock invocation) throws Throwable {
                Object[] args = invocation.getArguments();
                Holder<Boolean> newHolder = (Holder<Boolean>) args[0];
                newHolder.value = testBool;
            }
        }

     Boolean retBool = myClass.someMethod();

     assertTrue(retBool);
 }

This, for obvious reasons, is not exactly what I am doing. But it is a great generalized case.