/**
* Get index for slide
*
* @param \PhpOffice\PhpPresentation\Slide $slide
* @return int
* @throws \Exception
*/
public function getIndex(Slide $slide)
{
$index = null;
foreach ($this->slideCollection as $key => $value) {
if ($value->getHashCode() == $slide->getHashCode()) {
$index = $key;
break;
}
}
return $index;
}
