public void TestParentTestMessage()
{
// When subscribing to ParentTest Event the appropriate handler will be invoked when
// child (descendant) message types are published.
_bus.Subscribe <ParentTestEvent>(this);
var parentTestEvent = new ParentTestEvent();
_bus.Publish(parentTestEvent);
AssertEx.IsOrBecomesTrue(() => _testEventCount == 0, msg: $"Expected 0 got {_testEventCount}");
AssertEx.IsOrBecomesTrue(() => _parentTestEventCount == 1, msg: $"Expected 1 got {_parentTestEventCount}");
AssertEx.IsOrBecomesTrue(() => _childTestEventCount == 0, msg: $"Expected 0 got {_childTestEventCount}");
AssertEx.IsOrBecomesTrue(() => _grandChildTestEventCount == 0, msg: $"Expected 0 got {_grandChildTestEventCount}");
_bus.Subscribe <ChildTestEvent>(this);
var childTestEvent = new ChildTestEvent();
_bus.Publish(childTestEvent);
AssertEx.IsOrBecomesTrue(() => _testEventCount == 0, msg: $"Expected 0 got {_testEventCount}");
AssertEx.IsOrBecomesTrue(() => _parentTestEventCount == 2, msg: $"Expected 2 got {_parentTestEventCount}");
AssertEx.IsOrBecomesTrue(() => _childTestEventCount == 1, msg: $"Expected 1 got {_childTestEventCount}");
AssertEx.IsOrBecomesTrue(() => _grandChildTestEventCount == 0, msg: $"Expected 0 got {_grandChildTestEventCount}");
_bus.Subscribe <GrandChildTestEvent>(this);
var grandChildTestEvent = new GrandChildTestEvent();
_bus.Publish(grandChildTestEvent);
AssertEx.IsOrBecomesTrue(() => _testEventCount == 0, msg: $"Expected 0 got {_testEventCount}");
AssertEx.IsOrBecomesTrue(() => _parentTestEventCount == 3, msg: $"Expected 3 got {_parentTestEventCount}");
AssertEx.IsOrBecomesTrue(() => _childTestEventCount == 2, msg: $"Expected 2 got {_childTestEventCount}");
AssertEx.IsOrBecomesTrue(() => _grandChildTestEventCount == 1, msg: $"Expected 1 got {_grandChildTestEventCount}");
}
void IHandle <ParentTestEvent> .Handle(ParentTestEvent message) => Interlocked.Increment(ref _parentTestEventCount);
