@Test
public void testInitWithMockSSHSigner() {

    System.setProperty(ZTSConsts.ZTS_PROP_SSH_SIGNER_FACTORY_CLASS, "com.yahoo.athenz.zts.cert.impl.MockSSHSignerFactory");
    InstanceCertManager instanceCertManager = new InstanceCertManager(null, null, null, true);
    assertNotNull(instanceCertManager);
    instanceCertManager.shutdown();
    System.clearProperty(ZTSConsts.ZTS_PROP_SSH_SIGNER_FACTORY_CLASS);
}