def get(self, id, pk='id', deleted=False):
        try:
            if pk == 'id':
                id = int(id)
            if deleted:
                spec = {pk: id}
            else:
                spec = {pk: id, 'data': {'$exists': 1}}
            fields = {'_id': 0}
            row = self.db.docs.find_one(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return Document(**row)
        raise NotFoundError('%s %s not found' % (pk, id))
def drawMe(self, g):
        self.g = g
        r = 5
        # 繪出三個頂點
        self.p1.drawMe(self.g,r)
        self.p2.drawMe(self.g,r)
        self.p3.drawMe(self.g,r)
        line1 = Line(self.p1,self.p2)
        line2 = Line(self.p1,self.p3)
        line3 = Line(self.p2,self.p3)
        # 繪出三邊線
        line1.drawMe(self.g)
        line2.drawMe(self.g)
        line3.drawMe(self.g)