@Override
 public void setProperties(Map<String, Object> props) throws ConfigurationException {
   super.setProperties(props);
   if (props.get(PACKET_TYPES_KEY) != null) {
     packetTypes = (String[]) props.get(PACKET_TYPES_KEY);
   }
   // Make sure we can compare element names by reference
   // instead of String content
   for (int i = 0; i < packetTypes.length; i++) {
     packetTypes[i] = packetTypes[i].intern();
   }
   if (props.get(PREPEND_TEXT_KEY) != null) {
     prependText = (String) props.get(PREPEND_TEXT_KEY);
   }
 }