public class AccountAuthenticatorService extends Service {
  private static AccountAuthenticator AUTHENTICATOR = null;

  @Override
  public IBinder onBind(Intent intent) {
    return intent.getAction().equals(ACTION_AUTHENTICATOR_INTENT) ? getAuthenticator().getIBinder() : null;
  }

  private AccountAuthenticator getAuthenticator() {
    if (AUTHENTICATOR == null)
      AUTHENTICATOR = new AccountAuthenticator(this);
    return AUTHENTICATOR;
  }
}