docs: function(style, feature) {
          var context = OpenLayers.Util.extend({}, feature.attributes || feature.data);
          OpenLayers.Util.extend(context, this.context);
          
          for (var i in this.propertyStyles) {
              style[i] = OpenLayers.Style.createLiteral(style[i], context, feature, i);
          }
          return style;
      }