### Question:
TransitionAdapter implements GriffonPivotAdapter, org.apache.pivot.wtk.effects.TransitionListener { public void transitionCompleted(org.apache.pivot.wtk.effects.Transition arg0) { if (transitionCompleted != null) { transitionCompleted.call(arg0); } }  CallableWithArgs<Void> getTransitionCompleted(); void setTransitionCompleted(CallableWithArgs<Void> transitionCompleted); void transitionCompleted(org.apache.pivot.wtk.effects.Transition arg0);  }### Answer:
@Test public void testTransitionCompleted() { final boolean[] invoked = new boolean[1]; CallableWithArgs<Void> callable = new CallableWithArgs<Void>() { public Void call(Object... args) { invoked[0] = true; return null; } }; assertNull(adapter.getTransitionCompleted()); adapter.transitionCompleted(null); assertFalse(invoked[0]); adapter.setTransitionCompleted(callable); adapter.transitionCompleted(null); assertTrue(invoked[0]); }