docs: function ChartPoints () {
      var pointLinker = function (scope, element, attrs, chartCtrl) {
          var point = {};
          if (attrs.showPoint) {
              point.show =  (attrs.showPoint === 'true');
          }
          if (attrs.pointExpandEnabled) {
              if (!point.focus) {
                  point.focus = {"expand":{}};
              }
              point.focus.expand.enabled = (attrs.pointsFocusEnabled !== 'false');
          }
          if (attrs.pointExpandRadius) {
              if (!point.focus) {
                  pie.focus = {"expand":{}};
              }
              point.focus.expand.r = parseInt(attrs.pointFocusRadius);
          }
          if (attrs.pointRadius) {
              point.r = parseInt(attrs.pointRadius);
          }
          if (attrs.pointSelectRadius) {
              point.select = {"r":parseInt(attrs.pointSelectRadius)};
          }
          chartCtrl.addPoint(point);
      };
  
      return {
          require: '^c3chart',
          restrict: 'E',
          scope: {},
          replace: true,
          link: pointLinker
      };
  }