function LRUCache(capacity, init) 
{
  var capacity = capacity;
  var data = init || {};
  var timestamps = {};
  
  var getTimestamp = function() 
  {
    var time = Date.now();
    
    while(time === Date.now());
    return Date.now();
  };
  
  var findLRU = function() 
  {
    var keys = Object.keys(timestamps);
   
    return keys
      .reduce(function(acc, x) 
      { 
        if (timestamps[x] < acc.time) 
        { 
          return {key: x, time: timestamps[x]} ; 
        } else { return acc;} 
    }, {key: keys[0], time: timestamps[keys[0]] });
  };

  var cache = function(key, val) 
  {
    if (!key) return data;
    if (key && val) 
    {
      setCache(key, val); 
    }
    
    if (this.size > this.capacity) 
    {
      var lruItem = findLRU();
      deleteCache(lruItem.key);
    }
        
    return this;
  }.bind(this);