* @param accessor - the accessor.
* @param noEntryTransform - transform the no entry value, or NULL to ignore.
* @return The read only accessor.
*/
public static ReadOnlyFieldAccessor wrapMapField(final FieldAccessor accessor, final Function<Integer, Integer> noEntryTransform) {
return new ReadOnlyFieldAccessor() {
public Object get(Object instance) {
Object troveMap = accessor.get(instance);
// Apply transform as well
if (noEntryTransform != null)