    # File lib/rack/request.rb, line 66
        def scheme
          if @env['HTTPS'] == 'on'
            'https'
          elsif @env['HTTP_X_FORWARDED_SSL'] == 'on'
            'https'
          elsif @env['HTTP_X_FORWARDED_SCHEME']
            @env['HTTP_X_FORWARDED_SCHEME']
          elsif @env['HTTP_X_FORWARDED_PROTO']
            @env['HTTP_X_FORWARDED_PROTO'].split(',')[0]
          else
            @env["rack.url_scheme"]
          end
        end