def __init__(self, name, host='127.0.0.1', port=27017):
        self.name = name
        self.host = host
        self.port = port
def setTail(self, pt):
        self.pt = pt
        self.Tail.Eq(pt)
        self.Head.setPoint(self.pt.x + self.x, self.pt.y + self.y)