Suppose you've a trait that you will implement in child classes - ``` trait AppMessage {} ``` Given this injections ``` val mapBinder = ScalaMapBinder.newMapBinder[String, AppMessage](binder) mapBinder.addBinding("A").toInstance(new AppMessageSampleA) mapBinder.addBinding("B").toInstance(new AppMessageSampleB) ``` and calling them with `val map = injector.instance[im.Map[String, AppMessage]]` throws not found exception. Need to support `traits`