docs: function() {
          var activated = OpenLayers.Strategy.prototype.activate.apply(this, arguments);
          if(activated) {
              this.layer.events.on({
                  "refresh": this.load,
                  scope: this
              });
              if(this.layer.visibility == true || this.preload) {
                  this.load();
              } else {
                  this.layer.events.on({
                      "visibilitychanged": this.load,
                      scope: this
                  });
              }
          }
          return activated;
      }