code: void appendLog(String formattedMessage) {
      if (logTruncated) return;
      String combined = join(getLog(), formattedMessage);
      if (combined.length() > MAX_LOG_LENGTH) {
        String truncated = abbreviate(combined, MAX_LOG_LENGTH - TRUNCATION_BANNER.length() * 2 - 2);
        combined = join(new String[] {TRUNCATION_BANNER, truncated, TRUNCATION_BANNER}, "\n");
        logTruncated = true;
      }
      setLog(combined);
    }
docs: Appends a log message to the execution log. The first time the log exceeds MAX_LOG_LENGTH, it
  gets truncated and the TRUNCATION_BANNER gets added. Subsequent calls to appendLog will be
  ignored.
  
  @param formattedMessage The formatted message to append to the log.