anchor.diff:            let
               mountPoint' = escapeSystemdPath fs.mountPoint;
               device' = escapeSystemdPath fs.device;
  -            # -F needed to allow bare block device without partitions
  -            mkfsOpts = optional ((builtins.substring 0 3 fs.fsType) == "ext") "-F";
             in nameValuePair "mkfs-${device'}"
             { description = "Initialisation of Filesystem ${fs.device}";
               wantedBy = [ "${mountPoint'}.mount" ];
  
positive.code:       mountPoint = mkDefault name;
        device = mkIf (config.fsType == "tmpfs") (mkDefault config.fsType);
        options = mkIf config.autoResize "x-nixos.autoresize";
      };
  
    };
  
negative.code:         '';
        };
  
        formatOptions = mkOption {
          default = "";
          type = types.str;
          description = ''
            If <option>autoFormat</option> option is set specifies
            extra options passed to mkfs.
          '';
        };
  
        autoResize = mkOption {
          default = false;
          type = types.bool;
  