code: function(){
      var cached = {};
      var obj = {
          a: [1, 2, 3]
      }, json = "{\"a\":[1,2,3]}";
      
      if (typeof JSON != "undefined" && typeof JSON.stringify === "function" && JSON.stringify(obj).replace((/\s/g), "") === json) {
          // this is a working JSON instance
          return JSON;
      }
      if (Object.toJSON) {
          if (Object.toJSON(obj).replace((/\s/g), "") === json) {
              // this is a working stringify method
              cached.stringify = Object.toJSON;
          }
      }
      
      if (typeof String.prototype.evalJSON === "function") {
          obj = json.evalJSON();
          if (obj.a && obj.a.length === 3 && obj.a[2] === 3) {
              // this is a working parse method           
              cached.parse = function(str){
                  return str.evalJSON();
              };
          }
      }
      
      if (cached.stringify && cached.parse) {
          // Only memoize the result if we have valid instance
          getJSON = function(){
              return cached;
          };
          return cached;
      }
      return null;
  }
docs: A safe implementation of HTML5 JSON. Feature testing is used to make sure the implementation works.
  @return {JSON} A valid JSON conforming object, or null if not found.