/// <summary>
        /// Configures the data protection system to persist keys to the Windows registry.
        /// </summary>
        /// <param name="registryKey">The location in the registry where keys should be stored.</param>
        /// <returns>The 'this' instance.</returns>
        public DataProtectionConfiguration PersistKeysToRegistry(RegistryKey registryKey)
        {
            if (registryKey == null)
            {
                throw new ArgumentNullException(nameof(registryKey));
            }

            Use(DataProtectionServiceDescriptors.IXmlRepository_Registry(registryKey));
            return(this);
        }
        /// <summary>
        /// Configures the data protection system to persist keys to the Windows registry.
        /// </summary>
        /// <param name="builder">The <see cref="IDataProtectionBuilder"/>.</param>
        /// <param name="registryKey">The location in the registry where keys should be stored.</param>
        /// <returns>A reference to the <see cref="IDataProtectionBuilder" /> after this operation has completed.</returns>
        public static IDataProtectionBuilder PersistKeysToRegistry(this IDataProtectionBuilder builder, RegistryKey registryKey)
        {
            if (builder == null)
            {
                throw new ArgumentNullException(nameof(builder));
            }

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

            Use(builder.Services, DataProtectionServiceDescriptors.IXmlRepository_Registry(registryKey));
            return(builder);
        }