code: public void initTraceState(Map<String, Object> state) {
          Object traceId = state.get(Constants.HAWKULAR_APM_TRACEID);
          Object transaction = state.get(Constants.HAWKULAR_APM_TXN);
          Object level = state.get(Constants.HAWKULAR_APM_LEVEL);
          if (traceId != null) {
              setTraceId(traceId.toString());
          } else {
              log.severe("Trace id has not been propagated");
          }
          if (transaction != null) {
              setTransaction(transaction.toString());
          }
          if (level != null) {
              setReportingLevel(ReportingLevel.valueOf(level.toString()));
          }
      }
docs: Initialise the trace state from the supplied state.
  
  @param state The propagated state