logger.info("SuggestCreator is stopped.");
            }
            exitCode = Constants.EXIT_FAIL;
        } catch (final Throwable t) {
            logger.error("SuggestCreator terminated unexpectedly.", t);
            exitCode = Constants.EXIT_FAIL;
        } finally {
            if (systemMonitorTask != null) {
                systemMonitorTask.cancel();
            }
            destroyContainer();

  // here to provide error messages.
  // TODO(user): Some Strings used in the subclasses can be added as static Strings
  // here too.
  static final String ERROR_MODIFIABLE_SET = "Set returned is unexpectedly modifiable";
  static final String ERROR_SELF_LOOP = "self-loops are not allowed";
  static final String ERROR_ADDED_SELF_LOOP = "Should not be allowed to add a self-loop edge.";

     *
     * - _can_ be null without causing a runtime failure (because we don't want the interesting
     *   details of precondition failure to be hidden by an exception we throw about an unexpectedly
     *   null _failure message_)
     *
     * That combination upsets NullPointerTester, which wants any call that passes null for a
     * non-@Nullable parameter to trigger a NullPointerException.
     *

  // here to provide error messages.
  // TODO(user): Some Strings used in the subclasses can be added as static Strings
  // here too.
  static final String ERROR_MODIFIABLE_SET = "Set returned is unexpectedly modifiable";
  static final String ERROR_SELF_LOOP = "self-loops are not allowed";
  static final String ERROR_ADDED_SELF_LOOP = "Should not be allowed to add a self-loop edge.";

                logger.info("Crawler is stopped.");
            }
            exitCode = Constants.EXIT_FAIL;
        } catch (final Throwable t) {
            logger.error("Crawler terminated unexpectedly.", t);
            exitCode = Constants.EXIT_FAIL;
        } finally {
            if (commandThread != null && commandThread.isAlive()) {
                commandThread.interrupt();
            }

            service,
            from);
        checkState(
            servicesByState.put(to, service),
            "Service %s in the state map unexpectedly at %s",
            service,
            to);
        // Update the timer
        Stopwatch stopwatch = startupTimers.get(service);
        if (stopwatch == null) {

            service,
            from);
        checkState(
            servicesByState.put(to, service),
            "Service %s in the state map unexpectedly at %s",
            service,
            to);
        // Update the timer
        Stopwatch stopwatch = startupTimers.get(service);
        if (stopwatch == null) {

      try {
        logger.fine("$this starting to accept connections")
        acceptConnections()
      } catch (e: Throwable) {
        logger.log(Level.WARNING, "$this failed unexpectedly", e)
      }

      // Release all sockets and all threads, even if any close fails.
      serverSocket?.closeQuietly()

      val openClientSocket = openClientSockets.iterator()