def __repr__(self):
        return "<NamedRequirements({}{})>".format(
            self.name,
            ", filename='{}'".format(self.filename.name) if self.filename
            else "")
def drawMe(self, g, r):
        self.g = g
        self.r = r
        self.g.save()
        self.g.moveTo(self.x,self.y)
        self.g.beginPath()
        # 根據 r 半徑繪製一個圓代表點的所在位置
        self.g.arc(self.x, self.y, self.r, 0, 2*math.pi, true)
        self.g.moveTo(self.x,self.y)
        self.g.lineTo(self.x+self.r, self.y)
        self.g.moveTo(self.x, self.y)
        self.g.lineTo(self.x-self.r, self.y)
        self.g.moveTo(self.x, self.y)
        self.g.lineTo(self.x, self.y+self.r)
        self.g.moveTo(self.x, self.y)
        self.g.lineTo(self.x, self.y-self.r)
        self.g.restore()
        self.g.stroke()