anchor.diff:          type = types.lines;
           default = "";
           description = "Telemetry configuration";
  +      };
  +
  +      extraConfig = mkOption {
  +        type = types.lines;
  +        default = "";
  +        description = "Extra text appended to <filename>vault.hcl</filename>.";
         };
       };
     };
  
positive.code:         User = "vault";
          Group = "vault";
          PermissionsStartOnly = true;
          ExecStart = "${pkgs.vault}/bin/vault server -config ${configFile}";
          PrivateDevices = true;
          PrivateTmp = true;
          ProtectSystem = "full";
  
negative.code:         default = ''
            tls_min_version = "tls12"
          '';
          description = "Extra text appended to the listener section.";
        };
  
        storageBackend = mkOption {
  