/**
  * Initializes the Transfer manager to use a protocol to open connections.
  *
  * @param protocol Protocol to be used
  * @param properties Location of the properties files
  * @param mh Handler for the events produced by the connections
  */
 public static void init(String protocol, String properties, MessageHandler mh) {
   if (protocol.contentEquals("NIO")) {
     em = new NIOEventManager(mh);
   }
   try {
     em.init(properties);
   } catch (Exception e) {
     LOGGER.error(PROPERTIES_ERROR, e);
   }
   mh.init();
   em.start();
 }