docs: public boolean ordersEqual(OrderBook ob) {
  
      if (ob == null) {
        return false;
      }
  
      Date timestamp = new Date();
      OrderBook thisOb = new OrderBook(timestamp, this.getAsks(), this.getBids());
      OrderBook thatOb = new OrderBook(timestamp, ob.getAsks(), ob.getBids());
      return thisOb.equals(thatOb);
    }