This page redirects to an external site: https://developer.wordpress.org/reference/functions/validate_file_to_edit/
Make sure that the file that was requested to edit, is allowed to be edited.Function will die if if you are not allowed to edit the file.
<?php validate_file_to_edit( $file, $allowed_files ); ?>
null.
get_file_description( $file ) is located in wp-admin/includes/file.php#L172