### Question:
StatisticDataCollectionHelper { public static String getStatisticTraceId(MessageContext messageContext) { return (String) messageContext.getProperty(StatisticsConstants.FLOW_STATISTICS_ID) + System.nanoTime(); }  static String getStatisticTraceId(MessageContext messageContext); static int getFlowPosition(MessageContext messageContext); static int getParentFlowPosition(MessageContext messageContext, Integer newParentIndex); static List<Integer> getParentList(MessageContext messageContext); static boolean isOutOnlyFlow(MessageContext messageContext); static void collectData(MessageContext messageContext, boolean isContentAltering,
	                               Boolean isCollectingTracing, StatisticDataUnit statisticDataUnit); static void collectAggregatedParents(List<MessageContext> messages, MessageContext newCtx);  }### Answer:
@Test public void testGetStatisticTraceId() { String id = "testId"; messageContext.setProperty(StatisticsConstants.FLOW_STATISTICS_ID, id); String traceId = StatisticDataCollectionHelper.getStatisticTraceId(messageContext); Assert.assertTrue("should return concatenation of id and timestamp",traceId.contains(id)); }