code: protected synchronized Thread start(boolean forceRestart) {
          if (!forceRestart && isFixingActive()) {
              fixThread.interrupt();
          }
  
          if (forceRestart || !isFixingActive()) {
              fixThread = new FixThread();
              fixThread.start();
          }
          return fixThread;
      }
docs: Starts the background fixing activity.
  
  @param forceRestart
  If true, any ongoing fixing activity gets interrupted and the new one starts right away.