anchor.diff:  
       ${optionalString (elem cfg.relay.role ["bridge" "private-bridge"]) ''
         BridgeRelay 1
  -      ServerTransportPlugin obfs2,obfs3 exec ${pkgs.pythonPackages.obfsproxy}/bin/obfsproxy managed
  +      ServerTransportPlugin ${concatStringsSep "," cfg.relay.bridgeTransports} exec ${obfs4}/bin/obfs4proxy managed
         ExtORPort auto
         ${optionalString (cfg.relay.role == "private-bridge") ''
           ExtraInfoStatistics 0
  
positive.code:             </varlistentry>
              </variablelist>
            '';
          };
  
          nickname = mkOption {
  
negative.code:                 <para>
                    Regular bridge. Works like a regular relay, but
                    doesn't list you in the public relay directory and
                    hides your Tor node behind obfs4proxy.
                  </para>
  
                  <para>
  