public Task <ApplicationUser> FindAsync(UserLoginInfo login)
{
if (login == null)
{
throw new ArgumentNullException(nameof(login));
}
var identityUser = default(ApplicationUser);
var l = _externalLoginService.GetByProviderAndKey(login.LoginProvider, login.ProviderKey);
if (l != null)
{
identityUser = GetIdentityUser(l.User);
}
return(Task.FromResult(identityUser));
}