public async Task TestUnsubscribeClosingEvent()
{
var eventHandlerMock = new Mock <Action <object, EventArgs> >();
var mockedHandler = new EventHandler(eventHandlerMock.Object);
await RunPackageInitializeAsync();
_objectUnderTest.SubscribeClosingEvent(mockedHandler);
_objectUnderTest.UnsubscribeClosingEvent(mockedHandler);
((IVsPackage)_objectUnderTest).QueryClose(out _);
eventHandlerMock.Verify(f => f(It.IsAny <object>(), It.IsAny <EventArgs>()), Times.Never);
}
