public async Task Subscribe(Guid userId, Guid secondaryUserId)
{
var secondaryUser = await _usersRepository.GetUserById(secondaryUserId);
if (secondaryUser == null)
{
throw new ArgumentException("User not found");
}
await Task.WhenAll(_usersRepository.Subscribe(userId, secondaryUserId),
_feedService.AddAllUsersPhotoToFeed(userId, secondaryUserId));
}