Retrieve all bids in given auction.

def getBids(self, auction_id):
        """Retrieve all bids in given auction."""
        bids = {}
        rc = self.__ask__('doGetBidItem2', itemId=auction_id)
        if rc:
            for i in rc:
                i = i['bidsArray']
                bids[long(i['item'][1])] = {
                    'price': Decimal(i['item'][6]),
                    'quantity': int(i['item'][5]),
                    'date_buy': i['item'][7]
                }
        return bids