code: private static long getInvalidOffsetBehavior(Properties config) {
  		final String val = config.getProperty(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "largest");
  		if (val.equals("largest") || val.equals("latest")) { // largest is kafka 0.8, latest is kafka 0.9
  			return OffsetRequest.LatestTime();
  		} else {
  			return OffsetRequest.EarliestTime();
  		}
  	}
docs: Retrieve the behaviour of "auto.offset.reset" from the config properties.
  A partition needs to fallback to "auto.offset.reset" as default offset when
  we can't find offsets in ZK to start from in {@link StartupMode#GROUP_OFFSETS} startup mode.
  
  @param config kafka consumer properties
  @return either OffsetRequest.LatestTime() or OffsetRequest.EarliestTime()