public virtual async Task AddEmailAsync(TUser user, string email, string loginProvider = null, string loginProviderKey = null, CancellationToken cancellationToken = default(CancellationToken))
{
var existingEmail = FindIdentityEmail(user, email, loginProvider);
if (existingEmail != null)
{
existingEmail.LoginProvider = loginProvider;
existingEmail.LoginProviderKey = loginProviderKey;
Emails.Update(existingEmail);
return;
}
var identityEmail = CreateIdentityEmail(user, email, loginProvider, loginProviderKey);
await Emails.AddAsync(identityEmail, cancellationToken);
}