我需要按其子项计数排序父项：

function sort_terms_by_children_count ( $terms ) {
    $sort_terms_by_children_count = array();
    foreach($terms as $term) {
        $count = count (get_terms( $terms, array( \'child_of\' => $term->term_id, \'hide_empty\' => false, ) ));
        $sort_terms_by_children_count[$count] = $term;
}
    sort($sort_terms_by_children_count);

return $sort_terms_by_children_count;
}

$terms = get_terms(\'product_cat\');
$terms = $sort_terms_by_children_count($terms);