# File lib/bundler/source/rubygems.rb, line 265
      def normalize_uri(uri)
        uri = uri.to_s
        uri = "#{uri}/" unless uri =~ %r{/$}
        uri = URI(uri)
        raise ArgumentError, "The source must be an absolute URI. For example:\n" \
          "source 'https://rubygems.org'" if !uri.absolute? || (uri.is_a?(URI::HTTP) && uri.host.nil?)
        uri
      end