src/vs/workbench/contrib/preferences/browser/preferencesWidgets.ts/SettingsGroupTitleWidget/updateTwisty
class SettingsGroupTitleWidget:	private updateTwisty(collapse: boolean) {
		this.icon.classList.remove(...ThemeIcon.asClassNameArray(this.getTwistyIcon(!collapse)));
		this.icon.classList.add(...ThemeIcon.asClassNameArray(this.getTwistyIcon(collapse)));
	}