code: public final void sendingResponse(HttpTrace trace, TraceableResponse response,
  			Supplier<Principal> principal, Supplier<String> sessionId) {
  		setIfIncluded(Include.TIME_TAKEN,
  				() -> System.currentTimeMillis() - trace.getTimestamp().toEpochMilli(),
  				trace::setTimeTaken);
  		setIfIncluded(Include.SESSION_ID, sessionId, trace::setSessionId);
  		setIfIncluded(Include.PRINCIPAL, principal, trace::setPrincipal);
  		trace.setResponse(
  				new HttpTrace.Response(new FilteredTraceableResponse(response)));
  	}
docs: Ends the tracing of the exchange that is being concluded by sending the given
  {@code response}.
  @param trace the trace for the exchange
  @param response the response that concludes the exchange
  @param principal a supplier for the exchange's principal
  @param sessionId a supplier for the id of the exchange's session