code: function (graphicName)  {
          var id = this.container.id + "-" + graphicName;
          
          // check if symbol already exists in the cache
          var cache = this.symbolCache[id];
          if (cache) {
              return cache;
          }
          
          var symbol = OpenLayers.Renderer.symbol[graphicName];
          if (!symbol) {
              throw new Error(graphicName + ' is not a valid symbol name');
          }
  
          var symbolExtent = new OpenLayers.Bounds(
                                      Number.MAX_VALUE, Number.MAX_VALUE, 0, 0);
          
          var pathitems = ["m"];
          for (var i=0; i<symbol.length; i=i+2) {
              var x = symbol[i];
              var y = symbol[i+1];
              symbolExtent.left = Math.min(symbolExtent.left, x);
              symbolExtent.bottom = Math.min(symbolExtent.bottom, y);
              symbolExtent.right = Math.max(symbolExtent.right, x);
              symbolExtent.top = Math.max(symbolExtent.top, y);
  
              pathitems.push(x);
              pathitems.push(y);
              if (i == 0) {
                  pathitems.push("l");
              }
          }
          pathitems.push("x e");
          var path = pathitems.join(" ");
  
          var diff = (symbolExtent.getWidth() - symbolExtent.getHeight()) / 2;
          if(diff > 0) {
              symbolExtent.bottom = symbolExtent.bottom - diff;
              symbolExtent.top = symbolExtent.top + diff;
          } else {
              symbolExtent.left = symbolExtent.left + diff;
              symbolExtent.right = symbolExtent.right - diff;
          }
          
          cache = {
              path: path,
              size: symbolExtent.getWidth(), // equals getHeight() now
              left: symbolExtent.left,
              bottom: symbolExtent.bottom
          };
          this.symbolCache[id] = cache;
          
          return cache;
      }
docs: Method: importSymbol
  add a new symbol definition from the rendererer's symbol hash
  
  Parameters:
  graphicName - {String} name of the symbol to import
  
  Returns:
  {Object} - hash of {DOMElement} "symbol" and {Number} "size"