public void UnFollow(string SourceUserId, string targetUserId)
 {
     try
     {
         _graphDB.DeleteRelationship(SourceUserId, targetUserId, "Follow");
     }
     catch (Exception)
     {
         throw new FaildToConnectDbException();
     }
 }
 public void UnLikePost(string userId, string postId)
 {
     _graphDB.DeleteRelationship(userId, postId, "LikePost");
 }