function recycle(address farmer) internal {
        var elapsed = block.timestamp - recycled[farmer];
        if (elapsed == 0) {
            return;
        }
        var rotten = cellars[farmer];
        if (elapsed < decay) {
           rotten = cellars[farmer] * elapsed / decay;
        }
        if (rotten > 0) {
            cellars[farmer] -= rotten;
            trashes[farmer] += rotten;

            Transfer(farmer, 0, rotten);
        }
        recycled[farmer] = block.timestamp;
    }