src/vs/workbench/contrib/files/browser/explorerViewlet.ts/ExplorerViewPaneContainer/focus
class ExplorerViewPaneContainer:	override focus(): void {
		const explorerView = this.getView(VIEW_ID);
		if (explorerView && this.panes.every(p => !p.isExpanded())) {
			explorerView.setExpanded(true);
		}
		if (explorerView?.isExpanded()) {
			explorerView.focus();
		} else {
			super.focus();
		}
	}