private void addDifferenceOccurrences(List<TraceDifference> differences, String traceID) {
		
		for (TraceDifference difference : differences) {
			TraceDifference matchingDiff = null;
			for (TraceDifference diff : this.differenceOccurences.keySet()) {
				if (this.strictComparisons && diff.equals(difference) ||
						(!this.strictComparisons) && diff.relaxedEquals(difference)) {
					matchingDiff = diff;
					break;
				}
			}
			Set<String> traces = new HashSet<String>();
			traces.add(traceID);

			if (matchingDiff != null) {
				traces.addAll(differenceOccurences.get(matchingDiff));
				this.differenceOccurences.put(matchingDiff, traces);
			} else {
				this.differenceOccurences.put(difference, traces);
			}
		}
	}