caching.rb in caching-0.0.5

- old
+ new

@@ -1,7 +1,8 @@
 Dir["#{File.dirname(__FILE__)}/caching/*.rb"].each { |file| require file }
 require 'set'
 require 'base64'
+require 'concurrent'
 
 module Caching
 
   module ClassMethods
 