add node_modules to address #4364

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+# lru cache
+
+A cache object that deletes the least-recently-used items.
+
+## Usage:
+
+```javascript
+var LRU = require("lru-cache")
+  , options = { max: 500
+              , length: function (n) { return n * 2 }
+              , dispose: function (key, n) { n.close() }
+              , maxAge: 1000 * 60 * 60 }
+  , cache = LRU(options)
+  , otherCache = LRU(50) // sets just the max size
+
+cache.set("key", "value")
+cache.get("key") // "value"
+
+cache.reset()    // empty the cache
+```
+
+If you put more stuff in it, then items will fall out.
+
+If you try to put an oversized thing in it, then it'll fall out right
+away.
+
+## Keys should always be Strings or Numbers
+
+Note: this module will print warnings to `console.error` if you use a
+key that is not a String or Number.  Because items are stored in an
+object, which coerces keys to a string, it won't go well for you if
+you try to use a key that is not a unique string, it'll cause surprise
+collisions.  For example:
+
+```JavaScript
+// Bad Example!  Dont' do this!
+var cache = LRU()
+var a = {}
+var b = {}
+cache.set(a, 'this is a')
+cache.set(b, 'this is b')
+console.log(cache.get(a)) // prints: 'this is b'
+```
+
+## Options
+
+* `max` The maximum size of the cache, checked by applying the length
+  function to all values in the cache.  Not setting this is kind of
+  silly, since that's the whole purpose of this lib, but it defaults
+  to `Infinity`.
+* `maxAge` Maximum age in ms.  Items are not pro-actively pruned out
+  as they age, but if you try to get an item that is too old, it'll
+  drop it and return undefined instead of giving it to you.
+* `length` Function that is used to calculate the length of stored
+  items.  If you're storing strings or buffers, then you probably want
+  to do something like `function(n){return n.length}`.  The default is
+  `function(n){return 1}`, which is fine if you want to store `max`
+  like-sized things.
+* `dispose` Function that is called on items when they are dropped
+  from the cache.  This can be handy if you want to close file
+  descriptors or do other cleanup tasks when items are no longer
+  accessible.  Called with `key, value`.  It's called *before*
+  actually removing the item from the internal cache, so if you want
+  to immediately put it back in, you'll have to do that in a
+  `nextTick` or `setTimeout` callback or it won't do anything.
+* `stale` By default, if you set a `maxAge`, it'll only actually pull
+  stale items out of the cache when you `get(key)`.  (That is, it's
+  not pre-emptively doing a `setTimeout` or anything.)  If you set
+  `stale:true`, it'll return the stale value before deleting it.  If
+  you don't set this, then it'll return `undefined` when you try to
+  get a stale entry, as if it had already been deleted.
+
+## API
+
+* `set(key, value, maxAge)`
+* `get(key) => value`
+
+    Both of these will update the "recently used"-ness of the key.
+    They do what you think. `max` is optional and overrides the
+    cache `max` option if provided.
+
+* `peek(key)`
+
+    Returns the key value (or `undefined` if not found) without
+    updating the "recently used"-ness of the key.
+
+    (If you find yourself using this a lot, you *might* be using the
+    wrong sort of data structure, but there are some use cases where
+    it's handy.)
+
+* `del(key)`
+
+    Deletes a key out of the cache.
+
+* `reset()`
+
+    Clear the cache entirely, throwing away all values.
+
+* `has(key)`
+
+    Check if a key is in the cache, without updating the recent-ness
+    or deleting it for being stale.
+
+* `forEach(function(value,key,cache), [thisp])`
+
+    Just like `Array.prototype.forEach`.  Iterates over all the keys
+    in the cache, in order of recent-ness.  (Ie, more recently used
+    items are iterated over first.)
+
+* `keys()`
+
+    Return an array of the keys in the cache.
+
+* `values()`
+
+    Return an array of the values in the cache.
+
+* `length()`
+
+    Return total length of objects in cache taking into account
+    `length` options function.
+
+* `itemCount`
+
+    Return total quantity of objects currently in cache. Note, that
+    `stale` (see options) items are returned as part of this item
+    count.
+
+* `dump()`
+
+    Return an array of the cache entries ready for serialization and usage
+    with 'destinationCache.load(arr)`.
+
+* `load(cacheEntriesArray)`
+
+    Loads another cache entries array, obtained with `sourceCache.dump()`,
+    into the cache. The destination cache is reset before loading new entries