anchor.diff:  
         https_ports = ${toLua cfg.httpsPorts}
   
  +      ${ cfg.extraConfig }
  +
         ${lib.concatMapStrings (muc: ''
           Component ${toLua muc.domain} "muc"
               modules_enabled = { "muc_mam"; ${optionalString muc.vcard_muc ''"vcard_muc";'' } }
  
positive.code:             ${lib.optionalString (cfg.uploadHttp.userQuota != null) "http_upload_quota = ${toLua cfg.uploadHttp.userQuota}"}
              http_upload_path = ${toLua cfg.uploadHttp.httpUploadPath}
        ''}
  
        ${ cfg.extraConfig }
  
        ${ lib.concatStringsSep "\n" (lib.mapAttrsToList (n: v: ''
          VirtualHost "${v.domain}"
  
negative.code:         type = types.str;
          default = "en";
          description = "Default room language.";
        };
        extraConfig = mkOption {
          type = types.lines;
          default = "";
          description = "Additional MUC specific configuration";
        };
      };
    };
  