@Test
public void testRetrieveAlgoPrivateKeyInalid() {

    FilePrivateKeyStoreFactory factory = new FilePrivateKeyStoreFactory();
    PrivateKeyStore store = factory.create();
    String saveProp = System.getProperty(FilePrivateKeyStore.ATHENZ_PROP_PRIVATE_EC_KEY);
    assertNull(store.getPrivateKey("app", "localhost", "us-east-1", "ec"));
    assertNull(store.getPrivateKey("zms", "localhost", "us-east-1", "unknown"));
    System.clearProperty(FilePrivateKeyStore.ATHENZ_PROP_PRIVATE_EC_KEY);
    assertNull(store.getPrivateKey("zms", "localhost", "us-east-1", "ec"));
    System.setProperty(FilePrivateKeyStore.ATHENZ_PROP_PRIVATE_EC_KEY,
            "src/test/resources/ec_public_invalid.key");
    assertNull(store.getPrivateKey("zms", "localhost", "us-east-1", "ec"));
    if (saveProp == null) {
        System.clearProperty(FilePrivateKeyStore.ATHENZ_PROP_PRIVATE_EC_KEY);
    } else {
        System.setProperty(FilePrivateKeyStore.ATHENZ_PROP_PRIVATE_EC_KEY, saveProp);
    }
}