wp_ajax_add_user( string $action )

function wp_ajax_add_user( $action ) {
	if ( empty( $action ) ) {
		$action = 'add-user';
	}

	check_ajax_referer( $action );
	if ( ! current_user_can('create_users') )
		wp_die( -1 );
	if ( ! $user_id = edit_user() ) {
		wp_die( 0 );
	} elseif ( is_wp_error( $user_id ) ) {
		$x = new WP_Ajax_Response( array(
			'what' => 'user',
			'id' => $user_id
		) );
		$x->send();
	}
	$user_object = get_userdata( $user_id );

	$wp_list_table = _get_list_table('WP_Users_List_Table');

	$role = current( $user_object->roles );

	$x = new WP_Ajax_Response( array(
		'what' => 'user',
		'id' => $user_id,
		'data' => $wp_list_table->single_row( $user_object, '', $role ),
		'supplemental' => array(
			'show-link' => sprintf(
				/* translators: %s: the new user */
				__( 'User %s added' ),
				'<a href="#user-' . $user_id . '">' . $user_object->user_login . '</a>'
			),
			'role' => $role,
		)
	) );
	$x->send();
}