code: function OrderBook(currencyPair) {
      this._currencyPair = currencyPair;
  
      this._updateBufferMaxSize = OrderBook.DEFAULT_UPDATE_BUFFER_MAX_SIZE;
  
      this._wrapperPush = new PushWrapper();
      this._wrapperPublic = new PublicWrapper();
  
      this._statusRunning = false;
      this._statusSync = OrderBook.SYNC_STATUS_DESYNCHRONIZED;
  
      this._asks = new Table();
      this._bids = new Table();
  
      this._lastHandledSeq = -1;
  
      this._updateBuffer = new Array();
  
      this._eventEmitter = new events.EventEmitter();
  
      this._metrics = {
          "spread": 0,
          "askSumAmount": 0,
          "askSumTotal": 0,
          "bidSumAmount": 0,
          "bidSumTotal": 0
      };
  }
docs: /*
  Order book utility constructor.