/// <summary>
        /// Adds a scoped service of the type specified in <typeparamref name="TService"/> to the
        /// specified <see cref="IServiceCollection"/>.
        /// </summary>
        /// <typeparam name="TService">The type of the service to add.</typeparam>
        /// <param name="services">The <see cref="IServiceCollection"/> to add the service to.</param>
        /// <returns>A reference to this instance after the operation has completed.</returns>
        /// <seealso cref="ServiceLifetime.Scoped"/>
        public static IServiceCollection AddScoped <TService>(this PollyServiceCollection services)
            where TService : class
        {
            if (services == null)
            {
                throw new ArgumentNullException(nameof(services));
            }

            return(services.AddScoped(typeof(TService)));
        }
        /// <summary>
        /// Adds a scoped service of the type specified in <paramref name="serviceType"/> to the
        /// specified <see cref="IServiceCollection"/>.
        /// </summary>
        /// <param name="services">The <see cref="IServiceCollection"/> to add the service to.</param>
        /// <param name="serviceType">
        /// The type of the service to register and the implementation to use.
        /// </param>
        /// <returns>A reference to this instance after the operation has completed.</returns>
        /// <seealso cref="ServiceLifetime.Scoped"/>
        public static IServiceCollection AddScoped(
            this PollyServiceCollection services,
            Type serviceType)
        {
            if (services == null)
            {
                throw new ArgumentNullException(nameof(services));
            }

            if (serviceType == null)
            {
                throw new ArgumentNullException(nameof(serviceType));
            }

            return(services.AddScoped(serviceType, serviceType));
        }
        /// <summary>
        /// Adds a scoped service of the type specified in <typeparamref name="TService"/> with a
        /// factory specified in <paramref name="implementationFactory"/> to the specified <see cref="IServiceCollection"/>.
        /// </summary>
        /// <typeparam name="TService">The type of the service to add.</typeparam>
        /// <param name="services">The <see cref="IServiceCollection"/> to add the service to.</param>
        /// <param name="implementationFactory">The factory that creates the service.</param>
        /// <returns>A reference to this instance after the operation has completed.</returns>
        /// <seealso cref="ServiceLifetime.Scoped"/>
        public static IServiceCollection AddScoped <TService>(
            this PollyServiceCollection services,
            Func <IServiceProvider, TService> implementationFactory)
            where TService : class
        {
            if (services == null)
            {
                throw new ArgumentNullException(nameof(services));
            }

            if (implementationFactory == null)
            {
                throw new ArgumentNullException(nameof(implementationFactory));
            }

            return(services.AddScoped(typeof(TService), implementationFactory));
        }