@Test
@DisplayName("returns null when the url is null")
void crlFetcherReturnsNullWhenUrlIsNull() throws Exception
{

  Set<X509Certificate> trustSet = new HashSet<>();
  trustSet.add(certificate);
  HttpCrlFetcher crlFetcher = new HttpCrlFetcher(trustSet);
  X509CRL x509CRL = crlFetcher.download(null);
  Assertions.assertNull(x509CRL);
}