code: @Test public void connectionPooling() throws Exception {
    server.enqueue(new MockResponse().setBody("abc"));
    server.enqueue(new MockResponse().setBody("def"));
    server.enqueue(new MockResponse().setBody("ghi"));
    server.play();
    onSuccess(new Request.Builder().url(server.getUrl("/a")).build()).assertBody("abc");
    onSuccess(new Request.Builder().url(server.getUrl("/b")).build()).assertBody("def");
    onSuccess(new Request.Builder().url(server.getUrl("/c")).build()).assertBody("ghi");
    assertEquals(0,server.takeRequest().getSequenceNumber());
    assertEquals(1,server.takeRequest().getSequenceNumber());
    assertEquals(2,server.takeRequest().getSequenceNumber());
  }
  