WebDevStudios/Custom-Metaboxes-and-Fields-for-WordPress — pull request #526 by TweetPressFr (2014-04-16 15:26:23+00:00)
Title: Kinda of gracious degradation

As wp_enqueue_media has been added in WP 3.5.0 it could be a good thing to test its existence before using it. Simple way to avoid breaking admin page for unfortunate people running old versions of WP.