public function set(array $files)
    {
        if (!empty($files)) {
            foreach ($files as $_file) {
                if (is_array($_file) && isset($_file['file'])) {
                    $this->add(
                        $_file['file'],
                        isset($_file['media']) ? $_file['media'] : '',
                        isset($_file['condition']) ? $_file['condition'] : null
                    );
                } elseif (is_string($_file)) {
                    $this->add($_file);
                }
            }
        }
        return $this;
    }