### Question:
ServerImpl extends io.grpc.Server implements InternalInstrumented<ServerStats> { @Override public ListenableFuture<ServerStats> getStats() { ServerStats.Builder builder = new ServerStats.Builder() .setListenSockets(transportServer.getListenSockets()); serverCallTracer.updateBuilder(builder); SettableFuture<ServerStats> ret = SettableFuture.create(); ret.set(builder.build()); return ret; } ServerImpl(
      AbstractServerImplBuilder<?> builder,
      InternalServer transportServer,
      Context rootContext); @Override ServerImpl start(); @Override int getPort(); @Override List<ServerServiceDefinition> getServices(); @Override List<ServerServiceDefinition> getImmutableServices(); @Override List<ServerServiceDefinition> getMutableServices(); @Override ServerImpl shutdown(); @Override ServerImpl shutdownNow(); @Override boolean isShutdown(); @Override boolean awaitTermination(long timeout, TimeUnit unit); @Override void awaitTermination(); @Override boolean isTerminated(); @Override InternalLogId getLogId(); @Override ListenableFuture<ServerStats> getStats(); @Override HandlerRegistry getRegistry(); @Override String toString();  }### Answer:
@Test public void channelz_serverStats() throws Exception { createAndStartServer(); assertEquals(0, server.getStats().get().callsSucceeded); basicExchangeHelper(METHOD, "Lots of pizza, please", 314, null); assertEquals(1, server.getStats().get().callsSucceeded); }