EventListener[] listeners; listeners = instance.getPanelListeners(); assertEquals(0, listeners.length); } catch (NullPointerException expected) { listeners = instance.getPanelListeners(); assertEquals(0, listeners.length); listeners = instance.getPanelListeners(); assertEquals(0, listeners.length); listeners = instance.getPanelListeners(); assertEquals(1, listeners.length); assertSame(listener, listeners[0]); listeners = instance.getPanelListeners(); assertEquals(2, listeners.length); assertSame(listener, listeners[0]); listeners = instance.getPanelListeners(); assertEquals(1, listeners.length); assertSame(listener, listeners[0]); listeners = instance.getPanelListeners(); assertEquals(0, listeners.length);