### Question:
TextAreaSelectionAdapter implements GriffonPivotAdapter, org.apache.pivot.wtk.TextAreaSelectionListener { public void selectionChanged(org.apache.pivot.wtk.TextArea arg0, int arg1, int arg2) { if (selectionChanged != null) { selectionChanged.call(arg0, arg1, arg2); } }  CallableWithArgs<Void> getSelectionChanged(); void setSelectionChanged(CallableWithArgs<Void> selectionChanged); void selectionChanged(org.apache.pivot.wtk.TextArea arg0, int arg1, int arg2);  }### Answer:
@Test public void testSelectionChanged() { final boolean[] invoked = new boolean[1]; CallableWithArgs<Void> callable = new CallableWithArgs<Void>() { public Void call(Object... args) { invoked[0] = true; return null; } }; assertNull(adapter.getSelectionChanged()); adapter.selectionChanged(null, 0, 0); assertFalse(invoked[0]); adapter.setSelectionChanged(callable); adapter.selectionChanged(null, 0, 0); assertTrue(invoked[0]); }