src/vs/workbench/contrib/comments/browser/commentsView.ts/CommentsPanel/collapseAll
class CommentsPanel:	public collapseAll() {
		if (this.tree) {
			this.tree.collapseAll();
			this.tree.setSelection([]);
			this.tree.setFocus([]);
			this.tree.domFocus();
			this.tree.focusFirst();
		}
	}