DocumentUpdate deserializeUpdateFromFile(String fileName) throws IOException {
            byte[] data = DocumentTestCase.readFile(fileName);
            DocumentDeserializer buf = DocumentDeserializerFactory.createHead(docMan, GrowableByteBuffer.wrap(data));
            return new DocumentUpdate(buf);
        }
Tests applying and serializing document updates.

@author Einar M R Rosenvinge
document/src/test/java/com/yahoo/document/DocumentUpdateTestCase.java