public static String dateFormat(long time) {
    return DATE_FORMAT.format(new Date(time));
  }
This method is not currently implemented.

@param loggingEventMap a map of logging events

@return {@link LoggingEvent} decoded from the given logging event map.<br>
    Currently it throws an {@link UnsupportedOperationException} as the method is not implemented yet!
samza-log4j/src/main/java/org/apache/samza/logging/log4j/serializers/LoggingEventJsonSerde.java