uiu-cse/inc/acf/includes/ajax/class-acf-ajax-user-setting.php

<?php

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly
}

if ( ! class_exists( 'ACF_Ajax_User_Setting' ) ) :

	class ACF_Ajax_User_Setting extends ACF_Ajax {

		/** @var string The AJAX action name. */
		var $action = 'acf/ajax/user_setting';

		/** @var bool Prevents access for non-logged in users. */
		var $public = true;

		/**
		 * get_response
		 *
		 * Returns the response data to sent back.
		 *
		 * @date    31/7/18
		 * @since   5.7.2
		 *
		 * @param   array $request The request args.
		 * @return  mixed The response data or WP_Error.
		 */
		function get_response( $request ) {

			// update
			if ( $this->has( 'value' ) ) {
				return acf_update_user_setting( $this->get( 'name' ), $this->get( 'value' ) );

				// get
			} else {
				return acf_get_user_setting( $this->get( 'name' ) );
			}
		}
	}

	acf_new_instance( 'ACF_Ajax_User_Setting' );

endif; // class_exists check