private ISerializer getSerializer(Map conf) {
//get factory class name
String serializer_className = (String)conf.get(Config.TOPOLOGY_MULTILANG_SERIALIZER);
LOG.info("Storm multilang serializer: " + serializer_className);
ISerializer serializer = null;
try {
//create a factory class
Class klass = Class.forName(serializer_className);
//obtain a serializer object
Object obj = klass.newInstance();