anchor.diff:    cfg = config.services.caddy;
     configFile = pkgs.writeText "Caddyfile" cfg.config;
   
  -  # v2-specific options
  -  isCaddy2 = versionAtLeast cfg.package.version "2.0";
     tlsConfig = {
       apps.tls.automation.policies = [{
         issuer = {
  
positive.code:       example = "nginx";
        type = types.str;
        description = ''
          Name of the config adapter to use. Not applicable to Caddy v1.
          See https://caddyserver.com/docs/config-adapters for the full list.
        '';
      };
  
negative.code:     package = mkOption {
        default = pkgs.caddy;
        defaultText = "pkgs.caddy";
        example = "pkgs.caddy";
        type = types.package;
        description = ''
          Caddy package to use.
        '';
      };
    };
  