src/utils/lru.js
function LRUItem(key, value) {
  this.key = key;
  this.value = value;
  this.next = null;
  this.prev = null;
}
function LRUItem(key, value) {
  this.key = key;
  this.value = value;
  this.next = null;
  this.prev = null;
}
function LRUItem ( key , value ) { this . key = key ; this . value = value ; this . next = null ; this . prev = null ; }
Represents an LRU item.
@alias module:utils.LRUItem
@constructor
@private
@param {String} key
@param {Object} value
Represents an LRU item .