public IEnumerable <Thing> ColonyThingsWillingToBuy(Pawn playerNegotiator)
        {
            List <Thing> thingsWillingToBuy = new List <Thing>();

            foreach (Thing thing in TradeUtility.AllLaunchableThings(this.Map))
            {
                thingsWillingToBuy.Add(thing);
            }
            foreach (IntVec3 cell in this.OccupiedRect().Cells)
            {
                foreach (Thing thing in cell.GetThingList(this.Map))
                {
                    if ((TradeUtility.EverTradeable(thing.def)) &&
                        this.TraderKind.WillTrade(thing.def) &&
                        (thingsWillingToBuy.Contains(thing) == false))    // Do not count thing twice.
                    {
                        thingsWillingToBuy.Add(thing);
                    }
                }
            }
            return(thingsWillingToBuy);
        }