# File lib/openid_connect/client/registrar.rb, line 70
      def sector_identifier
        if valid_uri?(sector_identifier_uri)
          URI.parse(sector_identifier_uri).host
        else
          hosts = redirect_uris.collect do |redirect_uri|
            if valid_uri?(redirect_uri, nil)
              URI.parse(redirect_uri).host
            else
              nil
            end
          end.compact.uniq
          if hosts.size == 1
            hosts.first
          else
            nil
          end
        end
      end