To manually run this test, please follow the steps below:
1. Place caret at the end of 'hello world'.
2. Press Ctrl-Backspace (Alt-Backspace on macOS) to delete word backwards.
3. Place caret at the end of 'test2' => Press 'a' key.
4. Select 'test2a' => Press 'b' key.
5. Select 'b' => Bold text through context menu or Command-b on macOS.
6. Place caret at the end of 'test3' => Press 'a' key => Press Backspace key.
If a "PASS" result appears the test passes, otherwise it fails