code: function(eventTags, logger) {
      if (eventTags && eventTags.hasOwnProperty(VALUE_EVENT_METRIC_NAME)) {
        var rawValue = eventTags[VALUE_EVENT_METRIC_NAME];
        var parsedEventValue = parseFloat(rawValue);
        if (isNaN(parsedEventValue)) {
          logger.log(LOG_LEVEL.INFO, sprintf(LOG_MESSAGES.FAILED_TO_PARSE_VALUE, MODULE_NAME, rawValue));
          return null;
        }
        logger.log(LOG_LEVEL.INFO, sprintf(LOG_MESSAGES.PARSED_NUMERIC_VALUE, MODULE_NAME, parsedEventValue));
        return parsedEventValue;
      }
      return null;
    }
docs: Grab the event value from the event tags. "value" is a reserved keyword.
  @param {Object} eventTags
  @param {Object} logger
  @return {Number|null}