@Test
    public void testBytesBufferedChannelAfterMute() throws Exception {
        verifyNoUnnecessaryPollWithBytesBuffered(key -> ((KafkaChannel) key.attachment()).mute());
    }
A set of tests for the selector. These use a test harness that runs a simple socket server that echos back responses.
clients/src/test/java/org/apache/kafka/common/network/SslSelectorTest.java