nl_tokens: Construct the log watcher .
pl_tokens: function LogWatcher ( dirpath , maxfiles , ignoreInitial ) { _classCallCheck ( this , LogWatcher ) ; var _this = _possibleConstructorReturn ( this , ( LogWatcher . __proto__ || Object . getPrototypeOf ( LogWatcher ) ) . call ( this ) ) ; _this . _dirpath = dirpath || DEFAULT_SAVE_DIR ; _this . _filter = isCommanderLog ; _this . _maxfiles = maxfiles || 3 ; _this . _logDetailMap = { } ; _this . _ops = [ ] ; _this . _op = null ; _this . _startTime = new Date ( ) ; _this . _timer = null ; _this . _die = false ; _this . _ignoreInitial = ignoreInitial || <mask> ; _this . stopped = false ; _this . _loop ( ) ; _this . emit ( 'Started' ) ; return _this ; }