code: function drawPointShape(shapeObj, cfg, container) {
    var point = cfg.points[0];
    return container.addShape('circle', {
      attrs: Util.mix({
        x: point.x,
        y: point.y,
        r: 2,
        fill: cfg.color
      }, cfg.style)
    });
  }
docs: 当只有一个数据时绘制点