code: public RequestTag initializeAndTrackRequestTag(long requestId, String...requestInfo) {
          RequestTag requestTag = getRequestTagFor(requestInfo);
          if (tracingEnabled && !requestTag.isTracked()) {
              log.debug("Tags not found for this request: requestId={}, descriptor={}. Create request tag at this point.",
                      requestId, RequestTracker.buildRequestDescriptor(requestInfo));
              requestTag = new RequestTag(RequestTracker.buildRequestDescriptor(requestInfo), requestId);
              trackRequest(requestTag);
          }
  
          return requestTag;
      }
docs: This method first attempts to load a {@link RequestTag} from a request that is assumed to exist. However, if we
  work with clients or channels that do not attach tags to requests, then we initialize and track the request at
  the server side. In the worst case, we will have the ability of tracking a request from the server entry point
  onwards.
  
  @param requestId Alternative request id in the case there is no request id in headers.
  @param requestInfo Alternative descriptor to identify the call in the case there is no descriptor in headers.
  @return Request tag formed either from request headers or from arguments given.