code: void addTag(StringBuilder resultString, String tagName, String tagValue) {
  		resultString.append(" ");
  		resultString.append(sanitizeString(tagName));
  		resultString.append("=");
  		resultString.append(sanitizeString(tagValue));
  	}
docs: Add one tag, with the provided name and value, to the given result string.
  
  @param resultString - the string containing the metric name, timestamp, value, and possibly other content.
  @return String - the new result string with the tag appended.