Lazy-require DRb for ActiveSupport::Cache::DRbStore

activesupport/lib/active_support/cache/drb_store.rb

-require 'drb'
-
 module ActiveSupport
   module Cache
     class DRbStore < MemoryStore #:nodoc:
       attr_reader :address
 
       def initialize(address = 'druby://localhost:9192')
+        require 'drb' unless defined?(DRbObject)
         super()
         @address = address
         @data = DRbObject.new(nil, address)