public function check_authentication()
* Filters REST authentication errors.
* This is used to pass a WP_Error from an authentication method back to
* the API.
* Authentication methods should check first if they're being used, as
* multiple authentication methods can be enabled on a site (cookies,
* HTTP basic auth, OAuth). If the authentication method hooked in is
* not actually being attempted, null should be returned to indicate
* another authentication method should check instead. Similarly,
* callbacks should ensure the value is `null` before checking for
* A WP_Error instance can be returned if an error occurs, and this should
* match the format used by API methods internally (that is, the `status`
* data should be used). A callback can return `true` to indicate that
* the authentication method was used, and it succeeded.
* @since 4.4.0
* @param WP_Error|null|bool WP_Error if authentication error, null if authentication
* method wasn't used, true if authentication succeeded.
return apply_filters('rest_authentication_errors', null);