function getBookMedia( $reset = false ) {
		// Cheap cache
		static $book_media = null;
		if ( $reset || $book_media === null ) {
			$book_media = [];
			$args = [
				'post_type' => 'attachment',
				'posts_per_page' => -1,  // @codingStandardsIgnoreLine
				'post_status' => 'inherit',
				'no_found_rows' => true,
			];

			$attached_media = get_posts( $args );

			foreach ( $attached_media as $media ) {
				$book_media[ $media->ID ] = $media->guid;
			}
		}
		return $book_media;
	}