def __init__()

in app/marketplace.py [0:0]


    def __init__(self, name, quantity=0, timestamp=0):
        self.name = name
        self.quantity = int(quantity)
        if timestamp == 0:
            timestamp = datetime.utcnow().timestamp()
        self.timestamp = int(timestamp)
        self.datetime = datetime.fromtimestamp(self.timestamp).isoformat()