@Test
public void testIsRunningOnAppEngineProd() {

  SystemProperty.environment.set(SystemProperty.Environment.Value.Production);
  assertTrue(EnvUtil.isRunningOnAppEngineProd());
  SystemProperty.environment.set(SystemProperty.Environment.Value.Development);
  assertFalse(EnvUtil.isRunningOnAppEngineProd());
  System.clearProperty(EnvUtil.ENV_APPENGINE_RUNTIME);
  assertFalse(EnvUtil.isRunningOnAppEngineProd());
}