anchor.diff:  
           up = mkOption {
             default = "";
  -          type = types.string;
  +          type = types.lines;
             description = ''
               Shell commands executed when the instance is starting.
             '';
  
positive.code: 
          down = mkOption {
            default = "";
            type = types.string;
            description = ''
              Shell commands executed when the instance is shutting down.
            '';
  
negative.code: 
        type = types.attrsOf types.optionSet;
  
        options = {
  
          config = mkOption {
            type = types.lines;
            description = ''
              Configuration of this OpenVPN instance.  See
              <citerefentry><refentrytitle>openvpn</refentrytitle><manvolnum>8</manvolnum></citerefentry>
              for details.
  