code: 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;
      }
docs: Method: createLiterals
  creates literals for all style properties that have an entry in
  <this.propertyStyles>.
  
  Parameters:
  style   - {Object} style to create literals for. Will be modified
  inline.
  feature - {Object}
  
  Returns:
  {Object} the modified style