/// <summary>
 /// If the attribute ConnectionString is not null or empty, the value is looked up in ConnectionStrings,
 /// AppSettings, and Environment variables, in that order. Otherwise, the config ConnectionString is
 /// returned.
 /// </summary>
 /// <param name="configConnectionString">The connection string from the <see cref="NotificationHubsConfiguration"/>.</param>
 /// <param name="attributeConnectionString">The connection string from the <see cref="NotificationHubAttribute"/>.</param>
 /// <returns></returns>
 internal static string ResolveConnectionString(string configConnectionString, string attributeConnectionString)
 {
     if (!string.IsNullOrEmpty(attributeConnectionString))
     {
         return(NotificationHubsConfiguration.GetSettingFromConfigOrEnvironment(attributeConnectionString));
     }
     return(configConnectionString);
 }
 public NotificationHubAttributeBindingProvider(IConverterManager converterManager, NotificationHubsConfiguration config)
 {
     _converterManager = converterManager;
     _config           = config;
 }