@Override
        public void onPrimitive(FieldValue fv) {

            for (Map.Entry<String, IndexValue> entry : getVariables().entrySet()) {
                retVal += entry.getKey() + ": " + entry.getValue() + ",";
            }
            retVal += " - " + fv + "\n";
        }
Test for Document and all its features, including (de)serialization.

@author Thomas Gundersen
@author bratseth
document/src/test/java/com/yahoo/document/DocumentTestCase.java