private Task RemoveUserAsync(HubConnectionContext connection)
 {
     return(this.users.RemoveSubscriptionAsync(connection.UserIdentifier, connection, channelName =>
     {
         MsmqLog.Unsubscribe(this.logger, "user:" + connection.UserIdentifier);
         return Task.CompletedTask;
     }));
 }
 /// <summary>
 /// This takes <see cref="HubConnectionContext"/> because we want to remove the connection from the
 /// _connections list in OnDisconnectedAsync and still be able to remove groups with this method.
 /// </summary>
 private async Task RemoveGroupAsyncCore(HubConnectionContext connection, string groupName)
 {
     await this.groups.RemoveSubscriptionAsync(groupName, connection, channelName =>
     {
         MsmqLog.Unsubscribe(this.logger, channelName);
         return(Task.CompletedTask);
     });
 }