public static DAL.User FromEntityToDal(UserEntity user)
 {
     return new DAL.User()
     {
        Name = user.Name,
        FullName = user.FullName,
        AvatarURL = user.AvatarUrl
     };
 }
 Entities.UserEntity AddFollowing(UserEntity user)
 {
     return FromDalToEntity(this.UserDal.AddFollowing(user.Name));
 }