### Question:
BlockAdapter implements GriffonPivotAdapter, org.apache.pivot.wtk.text.BlockListener { public void horizontalAlignmentChanged(org.apache.pivot.wtk.text.Block arg0, org.apache.pivot.wtk.HorizontalAlignment arg1) { if (horizontalAlignmentChanged != null) { horizontalAlignmentChanged.call(arg0, arg1); } }  CallableWithArgs<Void> getHorizontalAlignmentChanged(); void setHorizontalAlignmentChanged(CallableWithArgs<Void> horizontalAlignmentChanged); void horizontalAlignmentChanged(org.apache.pivot.wtk.text.Block arg0, org.apache.pivot.wtk.HorizontalAlignment arg1);  }### Answer:
@Test public void testHorizontalAlignmentChanged() { final boolean[] invoked = new boolean[1]; CallableWithArgs<Void> callable = new CallableWithArgs<Void>() { public Void call(Object... args) { invoked[0] = true; return null; } }; assertNull(adapter.getHorizontalAlignmentChanged()); adapter.horizontalAlignmentChanged(null, null); assertFalse(invoked[0]); adapter.setHorizontalAlignmentChanged(callable); adapter.horizontalAlignmentChanged(null, null); assertTrue(invoked[0]); }