$newParentPermission = ($newParent instanceof Chapter) ? 'chapter-update' : 'book-update';
$hasNewParentPermission = userCan($newParentPermission, $newParent);
$newParentPermission = ($newParent instanceof Chapter) ? 'chapter-update' : 'book-update';
$hasNewParentPermission = userCan($newParentPermission, $newParent);