g.writeStringField( DirectMemoryConstants.KEY_FIELD_NAME, request.getKey() );
g.writeBooleanField( DirectMemoryConstants.PUT_FIELD_NAME, request.isUpdate() );
g.writeNumberField( DirectMemoryConstants.EXPIRES_IN_FIELD_NAME, request.getExpiresIn() );
// FIXME take care of NPE
// cache content generation
Serializer serializer = request.getSerializer();
// if no Object users are able to pass a string content