public IEnumerable <ProfileDto> GetFollowers(string userName)
{
if (userName.IsNullOrEmpty())
{
throw new ArgumentNullException(nameof(userName));
}
var followers = _profileProvider.GetFollowersByUserName(userName);
return(followers.Select(x =>
{
var result = _mapper.Map <ProfileDto>(x);
result.Followers = x.Followers.Select(p => _mapper.Map <ProfileDto>(p)).ToList();
return result;
}));
}