public async Task SendMessage(string[] user, string message)
{
//Sender id => this.Context.UserIdentifier);
List <string> tmplist = user.ToList();
int.TryParse(tmplist[tmplist.Count - 1], out int connectionID);
tmplist.RemoveAt(tmplist.Count - 1);
IReadOnlyList <string> list = tmplist;
await Clients.Users(list).SendAsync("ReceiveMessage", user[0], message);
await dataBaseRepository.SaveMessage(message, user[0], connectionID);
return;
}