code: public void resetState() {
      this.logWriteLock.lock();
      try {
        // Take a snapshot before resetting the state, for debugging purposes
        doSnapshot(false);
        // Clear the state
        clear();
        // Take another snapshot: if no snapshot is taken after clearing the state
        // and the manager is restarted, we will recover from the snapshot taken
        // before resetting the state, which would be really bad
        // This call will also init a new WAL
        doSnapshot(false);
      } catch (IOException e) {
        LOG.error("Snapshot failed when resetting state!", e);
        e.printStackTrace();
      } finally {
        this.logWriteLock.unlock();
      }
    }
docs: Resets the state of the transaction manager.