public void testReturning() throws Exception {
    assertNull(Callables.returning(null).call());

    Object value = new Object();
    Callable<Object> callable = Callables.returning(value);
    assertSame(value, callable.call());
    // Expect the same value on subsequent calls
    assertSame(value, callable.call());
  }

  @J2ktIncompatible
  @GwtIncompatible
  public void testAsAsyncCallable() throws Exception {

        .build()

    val startNanos = System.nanoTime()
    val call = client.newCall(request)

    // Schedule a job to cancel the call in 1 second.
    executor.schedule({
      System.out.printf("%.2f Canceling call.%n", (System.nanoTime() - startNanos) / 1e9f)
      call.cancel()
      System.out.printf("%.2f Canceled call.%n", (System.nanoTime() - startNanos) / 1e9f)
    }, 1, TimeUnit.SECONDS)

        localhostIpv4,
        localhostIpv6,
      )
    serverIpv4.enqueue(
      MockResponse(body = "unexpected call to IPv4"),
    )
    serverIpv6.enqueue(
      MockResponse(body = "hello from IPv6"),
    )

    val call = client.newCall(Request(url))
    val response = call.execute()
    assertThat(response.body.string()).isEqualTo("hello from IPv6")

// Stat captures time taken to call os.Stat
func Stat(name string) (info os.FileInfo, err error) {
	defer updateOSMetrics(osMetricStat, name)(err)
	return os.Stat(name)
}

// Create captures time taken to call os.Create
func Create(name string) (f *os.File, err error) {
	defer updateOSMetrics(osMetricCreate, name)(err)
	return os.Create(name)
}

// Fdatasync captures time taken to call Fdatasync

        .build()

    client.newCall(request).enqueue(
      object : Callback {
        override fun onFailure(
          call: Call,
          e: IOException,
        ) {
          e.printStackTrace()
        }

        override fun onResponse(
          call: Call,
          response: Response,
        ) {
          response.use {

    public int[] batchInsert(List<ClickLog> list, RequestOptionCall<BulkRequestBuilder> call) {
        return batchInsert(list, call, null);
    }

    public int[] batchInsert(List<ClickLog> list, RequestOptionCall<BulkRequestBuilder> call,
            RequestOptionCall<IndexRequestBuilder> entityCall) {
        return doBatchInsert(new BulkList<>(list, call, entityCall), null);
    }

    public int[] batchUpdate(List<ClickLog> list) {

    public int[] batchInsert(List<Group> list, RequestOptionCall<BulkRequestBuilder> call) {
        return batchInsert(list, call, null);
    }

    public int[] batchInsert(List<Group> list, RequestOptionCall<BulkRequestBuilder> call,
            RequestOptionCall<IndexRequestBuilder> entityCall) {
        return doBatchInsert(new BulkList<>(list, call, entityCall), null);
    }

    public int[] batchUpdate(List<Group> list) {

    public int[] batchInsert(List<AccessToken> list, RequestOptionCall<BulkRequestBuilder> call) {
        return batchInsert(list, call, null);
    }

    public int[] batchInsert(List<AccessToken> list, RequestOptionCall<BulkRequestBuilder> call,
            RequestOptionCall<IndexRequestBuilder> entityCall) {
        return doBatchInsert(new BulkList<>(list, call, entityCall), null);
    }

    public int[] batchInsert(List<DuplicateHost> list, RequestOptionCall<BulkRequestBuilder> call) {
        return batchInsert(list, call, null);
    }

    public int[] batchInsert(List<DuplicateHost> list, RequestOptionCall<BulkRequestBuilder> call,
            RequestOptionCall<IndexRequestBuilder> entityCall) {
        return doBatchInsert(new BulkList<>(list, call, entityCall), null);
    }

    public int[] batchInsert(List<ElevateWord> list, RequestOptionCall<BulkRequestBuilder> call) {
        return batchInsert(list, call, null);
    }

    public int[] batchInsert(List<ElevateWord> list, RequestOptionCall<BulkRequestBuilder> call,
            RequestOptionCall<IndexRequestBuilder> entityCall) {
        return doBatchInsert(new BulkList<>(list, call, entityCall), null);
    }