@Test
public void testAuthenticate_appEngineRunTimeSuccess() {

  System.setProperty(EnvUtil.ENV_APPENGINE_RUNTIME, "Production");
  request.addHeader(EndpointsPeerAuthenticator.HEADER_APPENGINE_PEER,
      EndpointsPeerAuthenticator.APPENGINE_PEER);
  assertTrue(authenticator.authenticate(request));
}