/**
* import font file
* @param string $fontFilePath to import
* @return int Book Font ID
*/
public function addFontToBook($fontFilePath, $assetId = null)
{
$result = $this->epub->importFontFile($fontFilePath, basename($fontFilePath), basename($fontFilePath), null, null, $assetId);
return $result['asset-id'];
}
