anchor.diff:        '';
       };
   
  +    extraConfig = mkOption {
  +      default = "";
  +      type = types.lines;
  +      description = "Extra configuration append to unit";
  +    };
     };
   
     linkOptions = commonNetworkOptions // {
  
positive.code:             ${attrsToSection x.routeConfig}
  
            '')}
          '';
      };
  
  
negative.code:         ''
            [Link]
            ${attrsToSection def.linkConfig}
  
            ${def.extraConfig}
          '';
      };
  
  