@Test
public void TestGetEtagForExistingPolicy_NoPolicyFile() throws Exception {

    PolicyUpdaterConfiguration configuration = new PolicyUpdaterConfiguration();
    configuration.init(pathToAthenzConfigFile, pathToZPUConfigFile);
    
    // Negative test, getEtagForExistingPolicy should return null when no policy file is found
    String matchingTag = PolicyUpdater.getEtagForExistingPolicy(null, configuration, "testDomain");
    Assert.assertNull(matchingTag);
}