check_multithread_status! (MemCache)

    # File lib/active_support/vendor/memcache-client-1.7.4/memcache.rb, line 891
      def check_multithread_status!
        return if @multithread

        if Thread.current[:memcache_client] != self.object_id
          raise MemCacheError, "You are accessing this memcache-client instance from multiple threads but have not enabled multithread support.\nNormally:  MemCache.new(['localhost:11211'], :multithread => true)\nIn Rails:  config.cache_store = [:mem_cache_store, 'localhost:11211', { :multithread => true }]\n"
        end
      end