Method getPaths

/**
 * Get a list of language files that have been loaded.
 *
 * @param   string  $extension  An optional extension name.
 *
 * @return  array
 *
 * @since   1.7.0
 */
public function getPaths($extension = null)
{
    if (isset($extension)) {
        if (isset($this->paths[$extension])) {
            return $this->paths[$extension];
        }
        return [];
    }
    return $this->paths;
}