WooCommerce - Attribute order alphabetical by name

<?php
// WooCommerce - Attribute order alphabetical by name
// default order is alphabetical by slug
add_filter( 'woocommerce_attribute_taxonomies', 'custom_attribute_sorting' );
function custom_attribute_sorting( $attribute_taxonomies ) {
  usort( $attribute_taxonomies, 'sort_by_attribute_label');
  return $attribute_taxonomies;
}
function sort_by_attribute_label( $a, $b ) {
  if( $a->attribute_label == $b->attribute_label ){ return 0; }
  return ($a->attribute_label < $b->attribute_label) ? -1 : 1;
}