increment

# File activesupport/lib/active_support/cache/mem_cache_store.rb, line 105
      def increment(key, amount = 1) # :nodoc:
        log("incrementing", key, amount)

        response = @data.incr(key, amount)
        response == Response::NOT_FOUND ? nil : response
      rescue MemCache::MemCacheError
        nil
      end