PHPePub\Core\EPub::isEPubVersion2 PHP Method

    function isEPubVersion2()
    {
        return $this->bookVersion === EPub::BOOK_VERSION_EPUB2;
    }

 /**
  * @param EPub   $book
  * @param string $value "landscape", "portrait" or "auto"
  */
 public static function setSpread($book, $value)
 {
     if (!$book->isEPubVersion2() && $value === self::SPREAD_NONE || $value === self::SPREAD_LANDSCAPE || $value === self::SPREAD_PORTRAIT || $value === self::SPREAD_BOTH || $value === self::SPREAD_AUTO) {
         $book->addCustomMetaProperty(self::RENDITION_SPREAD, $value);
     }
 }