public MailChimpProvider(
     IAntiforgery antiForgery,
     IHttpContextAccessor httpContextAccessor,
     IHostingEnvironment env,
     IMapper mapper,
     IAppSettings appSettings,
     MailChimpConfiguration configuration
     ) : base(antiForgery, httpContextAccessor, env, mapper, appSettings)
 {
     this.configuration = configuration;
 }
        public static OurOrdersBuilder UseMailChimp(this OurOrdersBuilder builder, string apiKey, string listId)
        {
            var config = new MailChimpConfiguration
            {
                ApiKey = apiKey,
                ListId = listId
            };

            builder.AppEvents.Configure += (sender, services) =>
            {
                services.AddTransient <INewsletterProvider, MailChimpProvider>();
                services.AddSingleton <MailChimpConfiguration>(config);
            };

            builder.HostServices.AddSingleton <MailChimpConfiguration>(config);

            builder.AppSettings.ExternalControllers.Add(typeof(MailChimpProvider));
            return(builder);
        }