protected function timestamped_endpoint( $url ) {
		// Make string for cache with GMT.
		// This is for caching thus you get
		// unique request only for 1 time in 10 minutes.
		$time = substr( date_i18n( 'YmdHi', false, true ), 0, -1 ) . '0';
		return add_query_arg( [
			'timestamp' => $time,
		], $url );
	}