public static IServiceCollection AddSessionFactoryProvider(this IServiceCollection services, Configuration cfg, string key)
        {
            bool boolFirstService = false;

            if (configProvider == null)
            {
                boolFirstService = true;
            }

            AddConfigurationProvider(services);
            configProvider.SetConfiguration(cfg, key);
            if (boolFirstService)
            {
                services.AddSingleton(provider =>
                {
                    var cfgProvider = provider.GetService <ISessionFactoryProvider>();
                    return(cfgProvider.GetConfiguration(key));
                });
                AddNHibernate(services, cfg);
            }
            return(services);
        }