### Question:
ListButtonSelectionAdapter implements GriffonPivotAdapter, org.apache.pivot.wtk.ListButtonSelectionListener { public void selectedIndexChanged(org.apache.pivot.wtk.ListButton arg0, int arg1) { if (selectedIndexChanged != null) { selectedIndexChanged.call(arg0, arg1); } }  CallableWithArgs<Void> getSelectedIndexChanged(); CallableWithArgs<Void> getSelectedItemChanged(); void setSelectedIndexChanged(CallableWithArgs<Void> selectedIndexChanged); void setSelectedItemChanged(CallableWithArgs<Void> selectedItemChanged); void selectedIndexChanged(org.apache.pivot.wtk.ListButton arg0, int arg1); void selectedItemChanged(org.apache.pivot.wtk.ListButton arg0, java.lang.Object arg1);  }### Answer:
@Test public void testSelectedIndexChanged() { final boolean[] invoked = new boolean[1]; CallableWithArgs<Void> callable = new CallableWithArgs<Void>() { public Void call(Object... args) { invoked[0] = true; return null; } }; assertNull(adapter.getSelectedIndexChanged()); adapter.selectedIndexChanged(null, 0); assertFalse(invoked[0]); adapter.setSelectedIndexChanged(callable); adapter.selectedIndexChanged(null, 0); assertTrue(invoked[0]); }