code: synchronized public boolean isBlacklisted(String trackerID) {
      TaskTrackerStatus status = getTaskTrackerStatus(trackerID);
      if (status != null) {
        return faultyTrackers.isBlacklisted(status.getHost());
      }
      return false;
    }
docs: Whether the tracker is blacklisted or not
  
  @param trackerID
  
  @return true if blacklisted, false otherwise