public function get_lessons( $return = 'lessons' ) {

		$lessons = array();
		foreach ( $this->get_sections( 'sections' ) as $section ) {
			$lessons = array_merge( $lessons, $section->get_lessons( 'posts' ) );
		}

		if ( 'ids' === $return ) {
			$ret = wp_list_pluck( $lessons, 'ID' );
		} elseif ( 'posts' === $return ) {
			$ret = $lessons;
		} else {
			$ret = array_map( 'llms_get_post', $lessons );
		}
		return $ret;

	}