@Test
  public void testSelectorPollReadSize() throws Exception {
    for (int socketBufSize : new int[]{applicationBufferSize, applicationBufferSize * 3, applicationBufferSize - 10}) {
      String connectionId = blockingSSLConnect(socketBufSize);
      String message =
          SelectorTest.randomString(socketBufSize * 2 + TestUtils.RANDOM.nextInt(socketBufSize), TestUtils.RANDOM);

      // Did not count the exact number of polls to completion since its hard to make that test deterministic.
      // i.e. EchoServer could respond slower than expected.
      assertEquals("Wrong echoed response", message, blockingRequest(connectionId, message));
    }
  }
selector.poll() should be able to fetch more data than netReadBuffer from the socket.
ambry-network/src/test/java/com/github/ambry/network/SSLSelectorTest.java