### Question:
ComponentClassAdapter implements GriffonPivotAdapter, org.apache.pivot.wtk.ComponentClassListener { public void focusedComponentChanged(org.apache.pivot.wtk.Component arg0) { if (focusedComponentChanged != null) { focusedComponentChanged.call(arg0); } }  CallableWithArgs<Void> getFocusedComponentChanged(); void setFocusedComponentChanged(CallableWithArgs<Void> focusedComponentChanged); void focusedComponentChanged(org.apache.pivot.wtk.Component arg0);  }### Answer:
@Test public void testFocusedComponentChanged() { final boolean[] invoked = new boolean[1]; CallableWithArgs<Void> callable = new CallableWithArgs<Void>() { public Void call(Object... args) { invoked[0] = true; return null; } }; assertNull(adapter.getFocusedComponentChanged()); adapter.focusedComponentChanged(null); assertFalse(invoked[0]); adapter.setFocusedComponentChanged(callable); adapter.focusedComponentChanged(null); assertTrue(invoked[0]); }