String typicalBlobJson = "{\"blobId\":\"xxxx-xxxx\"}";
BlobId id1 = mapper.readValue(typicalBlobJson, BlobId.class);
TestCase.assertEquals("xxxx-xxxx", id1.blobId);
String typicalJobJson = "{\"jobId\":\"yyyyyy\"}";
JobId id2 = mapper.readValue(typicalJobJson, JobId.class);
TestCase.assertEquals("yyyyyy", id2.jobId);
String emptyJson = "{}";
BlobId id3 = mapper.readValue(emptyJson, BlobId.class);
JobId id4 = mapper.readValue(emptyJson, JobId.class);
TestCase.assertNull(id3.blobId);
TestCase.assertNull(id4.jobId);
String extraStuffJson = "{\"blobId\":\"some-4by4\", \"junk\":0}";
BlobId id5 = mapper.readValue(extraStuffJson, BlobId.class);