@Before
  public void setUp() throws DigestException {
    digest =
        DescriptorDigest.fromHash(
            "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
  }
Tests for {@link RegistryClient}. More comprehensive tests can be found in the integration tests.
jib-core/src/test/java/com/google/cloud/tools/jib/registry/RegistryClientTest.java