code: public void serverCallStarted(ServerCallInfo<?, ?> callInfo) {
      for (StreamTracer tracer : tracers) {
        ((ServerStreamTracer) tracer).serverCallStarted(callInfo);
      }
    }
docs: See {@link ServerStreamTracer#serverCallStarted}.  For server-side only.
  
  <p>Called from {@link io.grpc.internal.ServerImpl}.