code: function () {
              var self = this,
                  LIFO_modifier = self._LIFO_modifier;
  
              // If already sorted return self
              if (self._sorted) {
                  return self;
              }
  
              // Sort entries
              self._values.sort(function (a, b) {
                      var retVal;
                      if (a.priority === b.priority) {
                          retVal = a.serial > b.serial;
                      }
                      else {
                          retVal = a.priority > b.priority;
                      }
                      return (retVal ? -1 : 1) * LIFO_modifier;
                  })
                  .forEach(function (item, index) {
                      self._keys[index] = item.key;
                      item.serial = index;
                  });
  
              // Set sorted to true and pointer to 0
              self._sorted = true;
              self.pointer = 0;
              return self;
          }
docs: Non api specific functions ------------------------------------------- Own Api functions ------------------------------------------- 
  Sorts priority list items based on `LIFO` flag.
  @method sjl.stdlib.PriorityList#sort
  @returns {sjl.stdlib.PriorityList} - Returns self.