public static function authenticate_old_user( WP_User $user ) {
		$cookie = user_switching_get_auth_cookie();
		if ( ! empty( $cookie ) ) {
			if ( self::secure_auth_cookie() ) {
				$scheme = 'secure_auth';
			} else {
				$scheme = 'auth';
			}

			$old_user_id = wp_validate_auth_cookie( end( $cookie ), $scheme );

			if ( $old_user_id ) {
				return ( $user->ID === $old_user_id );
			}
		}
		return false;
	}