void StateMachine <TInstance> .RaiseEvent(Composer composer, TInstance instance, Event @event)
        {
            composer.Execute(() =>
            {
                State <TInstance> state = _instanceStateAccessor.Get(instance);

                State <TInstance> instanceState = _stateCache[state.Name];

                return(composer.ComposeEvent(instance, instanceState, @event));
            });
        }