code: public static void shootBowgunCurrentTimeProvider(CurrentTimeProvider currentTimeProvider) {
          synchronized (SimpleTimeManager.class) { // to block while using provider
              assertUnlocked();
              if (logger.isInfoEnabled()) {
                  logger.info("...Shooting bowgun current-time provider: " + currentTimeProvider);
              }
              bowgunCurrentTimeProvider = currentTimeProvider;
              lock(); // auto-lock here, because of deep world
          }
      }
docs: ==========================