retrieve_cache_key

# File activesupport/lib/active_support/cache.rb, line 91
      def retrieve_cache_key(key)
        case
        when key.respond_to?(:cache_key) then key.cache_key
        when key.is_a?(Array)            then ['Array', *key.map { |element| retrieve_cache_key(element) }].to_param
        else                                  key.to_param
        end.to_s
      end