# File lib/faraday_middleware/response/caching.rb, line 60
    def cache_key(env)
      url = env[:url].dup
      if url.query && params_to_ignore.any?
        params = parse_query url.query
        params.reject! {|k,| params_to_ignore.include? k }
        url.query = params.any? ? build_query(params) : nil
      end
      url.normalize!

      Digest::SHA1.hexdigest(url.request_uri)
    end