wp_get_current_user（）函数在Rest API回调函数中不起作用

Question

请考虑以下php类扩展与Rest API相关的Wordpress的WP_REST_Controller类：

<?php
class MCQAcademy_Endpoint extends WP_REST_Controller {
    /**
     * Register the routes for the objects of the controller.
     */
    public function register_routes() {
        $version = '1';
        $namespace = 'custompath/v' . $version;
        $base = 'endpointbase';

        register_rest_route(
            $namespace,
            '/' . $base,
            array(
                array(
                    'methods'         => WP_REST_Server::READABLE,
                    'callback'        => array( $this, 'get_items' ),
                    'permission_callback' => array( $this, 'get_items_permissions_check' ),
                    'args'            => array(),
                )
            )
        );
    }

    /**
     *
     */
    public function get_items( $request ) {
        $rs = array(
            'data' => array(),
            'request' => array(
                'lang' => 'en',
            ),
        );

        $args = array();
        $items = get_posts( $args );

        foreach( $items as $item ) {
            $itemdata = $this->prepare_item_for_response( $item, $request );
            $rs['data'][] = $this->prepare_response_for_collection( $itemdata );
        }

        $rs['wp_get_current_user'] = wp_get_current_user(); // Does not output as expected

        return new WP_REST_Response( $rs, 200 );
    }

    /**
     * Check if a given request has access to get items
     */
    public function get_items_permissions_check( $request ) {
        return true; // to make readable by all
    }

    /**
     * Prepare the item for create or update operation
     */
    protected function prepare_item_for_database( $request ) {
        return $request;
    }

    /**
     * Prepare the item for the REST response
     */
    public function prepare_item_for_response( $item, $request ) {
        $data = array(
            'ID' => $item->ID,
            'post_content' => wpautop($item->post_content),
            'post_title' => $item->post_title,
        );

        return $data;
    }

    /**
     * Get the query params for collections
     */
    public function get_collection_params() {
        return array(
            'page'     => array(
                'description'        => 'Current page of the collection.',
                'type'               => 'integer',
                'default'            => 1,
                'sanitize_callback'  => 'absint',
            ),
            'per_page' => array(
                'description'        => 'Maximum number of items to be returned in result set.',
                'type'               => 'integer',
                'default'            => 10,
                'sanitize_callback'  => 'absint',
            ),
            'search'   => array(
                'description'        => 'Limit results to those matching a string.',
                'type'               => 'string',
                'sanitize_callback'  => 'sanitize_text_field',
            ),
        );
    }

    // Register our REST Server
    public function hook_rest_server(){
        add_action( 'rest_api_init', array( $this, 'register_routes' ) );
    }
}

$myEndpoint = new MCQAcademy_Endpoint();
$myEndpoint->hook_rest_server();

即使用户登录网站，除了调用wp_get_current_user()函数中的get_items()函数返回空用户外，一切进展顺利。

在Rest API端点函数中获取登录用户信息的解决方案是什么？