src/vs/editor/contrib/find/browser/findWidget.ts/SimpleButton/setExpanded
class SimpleButton:	public setExpanded(expanded: boolean): void {
		this._domNode.setAttribute('aria-expanded', String(!!expanded));
		if (expanded) {
			this._domNode.classList.remove(...ThemeIcon.asClassNameArray(findCollapsedIcon));
			this._domNode.classList.add(...ThemeIcon.asClassNameArray(findExpandedIcon));
		} else {
			this._domNode.classList.remove(...ThemeIcon.asClassNameArray(findExpandedIcon));
			this._domNode.classList.add(...ThemeIcon.asClassNameArray(findCollapsedIcon));
		}
	}