protected function set_columns() {

		$cols = array(
			'id'               => array(
				'exportable' => true,
				'title'      => __( 'ID', 'lifterlms' ),
				'sortable'   => true,
			),
			'name'             => array(
				'exportable' => true,
				'title'      => __( 'Name', 'lifterlms' ),
				'sortable'   => true,
			),
			'email'            => array(
				'exportable' => true,
				'title'      => __( 'Email', 'lifterlms' ),
				'sortable'   => true,
			),
			'enrolled_courses' => array(
				'exportable' => true,
				'title'      => __( 'Enrollment Date', 'lifterlms' ),
				'sortable'   => false,
			),
			'status'           => array(
				'filterable' => array(
					'enrolled'  => __( 'Enrolled', 'lifterlms' ),
					'expired'   => __( 'Expired', 'lifterlms' ),
					'cancelled' => __( 'Cancelled', 'lifterlms' ),
				),
				'exportable' => true,
				'title'      => __( 'Status', 'lifterlms' ),
				'sortable'   => false,
			),
		);

		return $cols;
	}