/// <summary>
 /// Removes a friendship from the database
 /// </summary>
 /// <param name="firstUserId"></param>
 /// <param name="secondUserId"></param>
 /// <returns></returns>
 public bool RemoveFriend(long firstUserId, long secondUserId)
 {
     return(firstUserId < secondUserId?_fr.RemoveFriendLink(firstUserId, secondUserId) : _fr.RemoveFriendLink(secondUserId, firstUserId));
 }