# File lib/aws/ec2/resource_tag_collection.rb, line 174
      def values_at(*keys)
        if cached = cached_tags
          return cached.values_at(*keys.map { |k| k.to_s })
        end
        keys = keys.map { |k| k.to_s }
        tag_set = @tags.
          filter("key", *keys).
          filtered_request(:describe_tags).tag_set
        hash = tag_set.inject({}) do |hash, tag|
          hash[tag.key] = tag.value
          hash
        end
        keys.map do |key|
          hash[key]
        end
      end