code: function(val, callback){
                  function finishEncode(val) {
                      callback(JSON.stringify(val));
                  }
                  this.decycle(val, finishEncode);
              }
docs: Encode the specified object as a string.  Because of the asynchronus
  conversion of Blob/File to string, the encode function requires
  a callback
  @param {Object} val the value to convert.
  @param {function} callback the function to call once conversion is
  complete.  The callback gets called with the converted value.