         case .Success(let sourceState,let destinationState):
             XCTAssert(sourceState.value == "Initial")
             XCTAssert(destinationState.value == "Passed")
-        case .Error(let error):
+        case .Error(_):
             XCTFail("There shouldn't be any errors")
         }
     }

        let transition = machine.fireEventNamed("Foo")
        
        switch transition {
        case .Success(let sourceState, let destinationState):
            XCTFail("Event does not exist and should not be fired")
        case .Error(let error):
            XCTAssert(error.code == Errors.Transition.UnknownEvent.rawValue)

        let transition = machine.fireEventNamed("Pass")
        
        switch transition {
        case .Success(_,_):
            XCTFail("success should not be fired")
        case .Error(let error):
            XCTAssert(error.code == Errors.Transition.TransitionDeclined.rawValue)
