decrement

# File activesupport/lib/active_support/cache/mem_cache_store.rb, line 68
      def decrement(key, amount = 1)
        log("decrement", key, amount)
        
        response = data.decr(key, amount) 
        response == Response::NOT_FOUND ? nil : response
      rescue MemCache::MemCacheError 
        nil
      end