@Override
        public Collection<V> values() {
            Collection<V> ret = new ArrayList<V>();
            for (Object v : map.values()) {
                ret.add(wrapValue(v));
            }
            return ret;
        }
Map of field values backed by a normal map of Java objects
@author vegardh
document/src/main/java/com/yahoo/document/datatypes/MapFieldValue.java