reset(level, msg, loggerName, time, sequenceNumber) {
    this.time_ = time || goog.now();
    this.level_ = level;
    this.msg_ = msg;
    this.loggerName_ = loggerName;
    this.exception_ = undefined;
    this.sequenceNumber_ = typeof sequenceNumber === 'number' ?
        sequenceNumber :
        goog.log.LogRecord.nextSequenceNumber_;
  }
Sets all fields of the log record.
@param {!goog.log.Level} level One of the level identifiers.
@param {string} msg The string message.
@param {string} loggerName The name of the source logger.
@param {number=} time Time this log record was created if other than
    now. If 0, we use #goog.now.
@param {number=} sequenceNumber Sequence number of this log record.
    This should only be passed in when restoring a log record from
    persistence.