Refactor `AbstractSimpleTransportTestCase` and `MockTransportService` to not use `Version.transportVersion` 
x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/transport/netty4/SimpleSecurityNetty4ServerTransportTests.java
}
    @Override
    protected Set<Setting<?>> getSupportedSettings() {
        HashSet<Setting<?>> availableSettings = new HashSet<>(super.getSupportedSettings());
        availableSettings.addAll(XPackSettings.getAllSettings());
        return availableSettings;
    }
    public void testConnectException() throws UnknownHostException {
        try {
            connectToNode(
                serviceA,
                new DiscoveryNode(
                    "C",
                    new TransportAddress(InetAddress.getByName("localhost"), 9876),
                    emptyMap(),
                    emptySet(),
                    Version.CURRENT
                )
            );
            fail("Expected ConnectTransportException");
        } catch (ConnectTransportException e) {
            assertThat(e.getMessage(), containsString("connect_exception"));
            assertThat(e.getMessage(), containsString("[127.0.0.1:9876]"));
            Throwable cause = ExceptionsHelper.unwrap(e, IOException.class);
            assertThat(cause, instanceOf(IOException.class));
        }
    }
    @Override
    public void testTcpHandshake() {
        assumeTrue("only tcp transport has a handshake method", serviceA.getOriginalTransport() instanceof TcpTransport);