src/vs/base/browser/ui/scrollbar/scrollbarVisibilityController.ts/ScrollbarVisibilityController/_reveal
class ScrollbarVisibilityController:	private _reveal(): void {
		if (this._isVisible) {
			return;
		}
		this._isVisible = true;

		// The CSS animation doesn't play otherwise
		this._revealTimer.setIfNotSet(() => {
			this._domNode?.setClassName(this._visibleClassName);
		}, 0);
	}