Docs: https://developer.wordpress.com/docs/api/1.1/post/sites/%24site/posts/%24post/related/ Expect: not only `post_id`, but also return all attributes of the related post
Docs: https://developer.wordpress.com/docs/api/1.1/post/sites/%24site/posts/%24post/related/
Expect: not only
post_id, but also return all attributes of the related post