attachment_fields_to_save, array( $this, save_attachment

Warning: Undefined array key 0 in /home/c6974294/public_html/wp-plugin-api.com/wp-content/themes/wordpress-hooks/functions.php on line 33

Warning: Attempt to read property "name" on null in /home/c6974294/public_html/wp-plugin-api.com/wp-content/themes/wordpress-hooks/functions.php on line 33
See hook in action

See this hook used in plugins:

Select Pluginadvanced-custom-fields.6.8.6