/**
  * @param Post $post
  *
  * @return PostMeta|null
  */
 public function getThumbnailPostId(Post $post)
 {
     return $this->getPostMeta($post->getId(), '_thumbnail_id', true);
 }
 /**
  * @param string $permalinkStructure
  * @param Post   $post
  *
  * @return string
  */
 public function replacePostArguments($permalinkStructure, Post $post)
 {
     $postDate = $post->getDate();
     $permalinkStructure = str_replace('%year%', $postDate->format('Y'), $permalinkStructure);
     $permalinkStructure = str_replace('%monthnum%', $postDate->format('m'), $permalinkStructure);
     $permalinkStructure = str_replace('%day%', $postDate->format('d'), $permalinkStructure);
     $permalinkStructure = str_replace('%post_id%', $post->getId(), $permalinkStructure);
     $permalinkStructure = str_replace('%postname%', $post->getName(), $permalinkStructure);
     return $permalinkStructure;
 }