@Test
public void testValidateDnsNamesNoValues() throws IOException {

    Path path = Paths.get("src/test/resources/valid_cn_only.csr");
    String csr = new String(Files.readAllBytes(path));
    X509CertRequest certReq = new X509CertRequest(csr);
    assertNotNull(certReq);
    DataCache athenzSysDomainCache = Mockito.mock(DataCache.class);
    Mockito.when(athenzSysDomainCache.getProviderDnsSuffixList("provider"))
            .thenReturn(null);
    assertTrue(certReq.validateDnsNames("domain", "service1", "provider", athenzSysDomainCache,
            null, null, null, null));
}