Frontend\Core\Engine\Form::addFile PHP Method

    public function addFile($name, $class = null, $classError = null)
    {
        $name = (string) $name;
        $class = $class !== null ? (string) $class : 'inputFile';
        $classError = $classError !== null ? (string) $classError : 'inputFileError';
        // create and return a file field
        return parent::addFile($name, $class, $classError);
    }