public Task CreateAsync(TUser user)
{
if (user == null)
{
throw new ArgumentNullException("user");
}
TUser result = IdentityUserRepository.Add(user) as TUser;
if (result != null)
{
return(Task.FromResult <TUser>(result));
}
return(Task.FromResult <TUser>(null));
//return Task.FromResult<object>(null);
}