code: private AttributeValue getVersionAttributeValue(final Method getter, Object getterReturnResult) {
          ArgumentMarshaller marshaller = reflector.getVersionedArgumentMarshaller(getter, getterReturnResult);
          return marshaller.marshall(getterReturnResult);
      }
docs: Gets the attribute value object corresponding to the
  {@link DynamoDBVersionAttribute} getter, and its result, given. Null
  values are assumed to be new objects and given the smallest possible
  positive value. Non-null values are incremented from their current value.