public static void AddAssembly(this HttpConfiguration httpConfiguration, Assembly assembly)
        {
            Dispatcher.IAssembliesResolver existingAssembliesResolver = GetAssembliesResolver(httpConfiguration);
            ICollection <Assembly>         existingAssemblies         = existingAssembliesResolver.GetAssemblies();

            if (!existingAssemblies.Contains(assembly))
            {
                AssembliesResolver assembliesResolver = new AssembliesResolver(existingAssemblies);
                assembliesResolver.Add(assembly);
                httpConfiguration.Services.Replace(typeof(Dispatcher.IAssembliesResolver), assembliesResolver);
            }
        }