code: @Override
      public Object onRequest(ActivityRuntimeContext context, Object content, Map<String,String> headers, Object connection) {
          if (connection instanceof HttpConnection) {
              HttpConnection httpConnection = (HttpConnection)connection;
              Tracing tracing = TraceHelper.getTracing("mdw-adapter");
              HttpTracing httpTracing = HttpTracing.create(tracing).toBuilder()
                      .clientParser(new HttpClientParser() {
                          public <Req> void request(HttpAdapter<Req, ?> adapter, Req req, SpanCustomizer customizer) {
                              // customize span name
                              customizer.name(context.getActivity().oneLineName());
                          }
                      })
                      .build();
              Tracer tracer = httpTracing.tracing().tracer();
              handler = HttpClientHandler.create(httpTracing, new ClientAdapter());
              injector = httpTracing.tracing().propagation().injector((httpRequest, key, value) -> headers.put(key, value));
              span = handler.handleSend(injector, new HttpRequest(httpConnection));
              scope = tracer.withSpanInScope(span);
          }
          return null;
      }
docs: Only for HTTP.