Error: `parentNode` property of given node is `undefined`

Just for some hours now, our gulp build process stopped working due to an error in `gulp-javascript-obfuscator`:
```
C:\...\node_modules\gulp-javascript-obfuscator\
node_modules\javascript-obfuscator\dist\webpack:\JavaScriptObfuscator\src\node\N
odeUtils.ts:237
throw new ReferenceError('`parentNode`property of given node is `un
defined`');
^
ReferenceError: `parentNode` property of given node is `undefined`
```
(Note that I have "..." the path to the actual folder.)

After quickly digging into the problem, I have found that `javascript-obfuscator` has release v0.17.0 just today (some hours) ago. If I manually downgrade inside the `gulp-javascript-obfuscator` the `javascript-obfuscator` to `0.16.0` (instead of `latest`) it works again. I know this cannot be the actual solution, but it could be a starting point however.

Any suggestions?
Thanks in advance.
Please, if more information is required from my side, tell me.

首先使用 javascript-obfuscator 0.17.0 重現 gulp 建置，並與報告中可正常運作的 0.16.0 設定進行比較。檢查與回報的 nodeUtils.ts:237 錯誤相關的相依性行為；當 plugin 使用受影響的相依性版本成功建置，或記錄了相容的版本限制時，即視為完成。

由索引模型根據 Issue 內容生成。