code: public void start() {
          if (workers != null) throw new UnsupportedOperationException("Please shutdown connector!");
  
          if (LOGGER.isLoggable(Level.INFO))
              LOGGER.info("Starting " + name + " with " + config.getWorkerCount() + " workers");
  
          handlers = new ConcurrentLinkedQueue<TcpServerHandler>();
          handlers.add(new TcpServerAcceptor(config, handlers));
  
          workers = new Thread[config.getWorkerCount()];
          for (int i = 0; i < workers.length; i++) {
              workers[i] = new TcpServerWorker(handlers);
          }
  
          for (final Thread worker : workers) worker.start();
  
          if (LOGGER.isLoggable(Level.INFO))
              LOGGER.info(name + " started");
      }
docs: This method starts waiting incoming connections for proxy to remote host.
  Method return control when all worker will be started, it isn't block.
  
  @throws UnsupportedOperationException - if you try to start already started connector