ensureExt example

    public function locateFile(string $file, ?string $folder = null, string $ext = 'php')
    {
        $file = $this->ensureExt($file, $ext);

        // Clears the folder name if it is at the beginning of the filename         if (! empty($folder) && strpos($file, $folder) === 0) {
            $file = substr($file, strlen($folder . '/'));
        }

        // Is not namespaced? Try the application folder.         if (strpos($file, '\\') === false) {
            return $this->legacyLocate($file, $folder);
        }