How to use the bfx-api-node-models.OrderBook function in bfx-api-node-models

let data = getMessagePayload(msg)

    if (this._manageOrderBooks) {
      const err = this._updateManagedOB(symbol, data, raw)

      if (err) {
        this.emit('error', err)
        return
      }

      data = this._orderBooks[symbol]
    }

    // Always transform an array of entries
    if (this._transform) {
      data = new OrderBook((Array.isArray(data[0]) ? data : [data]), raw)
    }

    const internalMessage = [chanData.chanId, 'orderbook', data]
    internalMessage.filterOverride = [
      chanData.symbol,
      chanData.prec,
      chanData.len
    ]

    this._propagateMessageToListeners(internalMessage, chanData, false)
    this.emit('orderbook', symbol, data)
  }

getOB (symbol) {
    if (!this._orderBooks[symbol]) return null

    return new OrderBook(this._orderBooks[symbol])
  }