private void processTuple(String counterName, Tuple tuple) {
		String[] path = StringUtils.tokenizeToStringArray(fieldName, ".");
		processValueForCounter(counterName, tuple, path);
	}
Counts the occurrence of values for a set of JavaBean properties or Tuple fields using a FieldValueCounterRepository.
Assumes a String payload is JSON and will convert it to a Tuple.

@author Mark Pollack
@author David Turanski
@author Mark Fisher
spring-xd-analytics/src/main/java/org/springframework/xd/analytics/metrics/integration/FieldValueCounterHandler.java