fetch

# File lib/bundler/fetcher/downloader.rb, line 14
      def fetch(uri, headers = {}, counter = 0)
        raise HTTPError, "Too many redirects" if counter >= redirect_limit

        response = request(uri, headers)
        Bundler.ui.debug("HTTP #{response.code} #{response.message} #{uri}")

        case response
        when Net::HTTPSuccess, Net::HTTPNotModified
          response
        when Net::HTTPRedirection
          new_uri = URI.parse(response["location"])
          if new_uri.host == uri.host
            new_uri.user = uri.user
            new_uri.password = uri.password
          end
          fetch(new_uri, headers, counter + 1)
        when Net::HTTPRequestedRangeNotSatisfiable
          new_headers = headers.dup
          new_headers.delete("Range")
          new_headers["Accept-Encoding"] = "gzip"
          fetch(uri, new_headers)
        when Net::HTTPRequestEntityTooLarge
          raise FallbackError, response.body
        when Net::HTTPUnauthorized
          raise AuthenticationRequiredError, uri.host
        when Net::HTTPNotFound
          raise FallbackError, "Net::HTTPNotFound"
        else
          raise HTTPError, "#{response.class}#{": #{response.body}" unless response.body.empty?}"
        end
      end