public T Get <T>(Identifier id)
{
var type = typeof(T);
object instance = null;
if (classFactories.ContainsKey(type) && classFactories[type].ContainsKey(id))
{
instance = classFactories[type][id]();
}
else if (services.ContainsKey(type) && services[type].ContainsKey(id))
{
instance = services[type][id];
}
if (instance == null)
{
throw new NullReferenceException($"No class of type '{type.GetFriendlyName()}' with id '{id}' found");
}
return((T)instance);
}