src/vs/platform/actions/browser/dropdownWithPrimaryActionViewItem.ts/DropdownWithPrimaryActionViewItem/setFocusable
class DropdownWithPrimaryActionViewItem:	override setFocusable(focusable: boolean): void {
		if (focusable) {
			this._primaryAction.element!.tabIndex = 0;
		} else {
			this._primaryAction.element!.tabIndex = -1;
			this._dropdown.setFocusable(false);
		}
	}