protected function tilNextMillis($lastTimestamp) {
        $timestamp = $this->timeGen();
        while ($timestamp <= $lastTimestamp) {
            $timestamp = $this->timeGen();
        }
        return $timestamp;
    }
protected function tilNextMillis($lastTimestamp) {
        $timestamp = $this->timeGen();
        while ($timestamp <= $lastTimestamp) {
            $timestamp = $this->timeGen();
        }
        return $timestamp;
    }
protected function tilNextMillis ( $ lastTimestamp ) { $ timestamp = $ this -> timeGen ( ) ; while ( $ timestamp <= $ lastTimestamp ) { $ timestamp = $ this -> timeGen ( ) ; } return $ timestamp ; }
get next micro time
get next micro time