public function set_columns() {
		return array(
			'id'        => array(
				'title' => __( 'ID', 'lifterlms' ),
			),
			'name'      => array(
				'title'    => __( 'Name', 'lifterlms' ),
				'sortable' => true,
			),
			'status'    => array(
				'title' => __( 'Status', 'lifterlms' ),
			),
			'grade'     => array(
				'title' => __( 'Grade', 'lifterlms' ),
			),
			'progress'  => array(
				'title' => __( 'Progress', 'lifterlms' ),
			),
			'updated'   => array(
				'title'    => __( 'Updated', 'lifterlms' ),
				'sortable' => true,
			),
			'completed' => array(
				'title' => __( 'Completed', 'lifterlms' ),
			),
		);
	}