code: public void outboundMessageSent(int seqNo, long optionalWireSize, long optionalUncompressedSize) {
      for (StreamTracer tracer : tracers) {
        tracer.outboundMessageSent(seqNo, optionalWireSize, optionalUncompressedSize);
      }
    }
docs: See {@link StreamTracer#outboundMessageSent}.
  
  <p>Called from {@link io.grpc.internal.Framer}.