code: function(renderIntent, property, symbolizers, context) {
          var rules = [];
          for (var value in symbolizers) {
              rules.push(new OpenLayers.Rule({
                  symbolizer: symbolizers[value],
                  context: context,
                  filter: new OpenLayers.Filter.Comparison({
                      type: OpenLayers.Filter.Comparison.EQUAL_TO,
                      property: property,
                      value: value
                  })
              }));
          }
          this.styles[renderIntent].addRules(rules);
      }
docs: Method: addUniqueValueRules
  Convenience method to create comparison rules for unique values of a
  property. The rules will be added to the style object for a specified
  rendering intent. This method is a shortcut for creating something like
  the "unique value legends" familiar from well known desktop GIS systems
  
  Parameters:
  renderIntent - {String} rendering intent to add the rules to
  property     - {String} values of feature attributes to create the
  rules for
  symbolizers  - {Object} Hash of symbolizers, keyed by the desired
  property values
  context      - {Object} An optional object with properties that
  symbolizers' property values should be evaluated
  against. If no context is specified, feature.attributes
  will be used