Refactor `AbstractSimpleTransportTestCase` and `MockTransportService` to not use `Version.transportVersion` 
test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java
}
            @Override
            public void handleResponse(StringMessageResponse response) {
                assertThat("pong", equalTo(response.message));
                assertEquals("ping_user", threadPool.getThreadContext().getHeader("test.ping.user"));
                assertNull(threadPool.getThreadContext().getHeader("test.pong.user"));
                assertSame(context, threadPool.getThreadContext().getTransient("my_private_context"));
                threadPool.getThreadContext().putHeader("some.temp.header", "booooom");
            }
            @Override
            public void handleException(TransportException exp) {
                logger.error("Unexpected failure", exp);
                fail("got exception instead of a response: " + exp.getMessage());
            }
        };
        StringMessageRequest ping = new StringMessageRequest("ping");
        threadPool.getThreadContext().putHeader("test.ping.user", "ping_user");
        threadPool.getThreadContext().putTransient("my_private_context", context);
        Future<StringMessageResponse> res = submitRequest(serviceB, nodeA, "internal:ping_pong", ping, responseHandler);
        StringMessageResponse message = res.get();
        assertThat("pong", equalTo(message.message));
        assertEquals("ping_user", threadPool.getThreadContext().getHeader("test.ping.user"));
        assertSame(context, threadPool.getThreadContext().getTransient("my_private_context"));
        assertNull("this header is only visible in the handler context", threadPool.getThreadContext().getHeader("some.temp.header"));
    }
    public void testLocalNodeConnection() throws InterruptedException {
        assertTrue("serviceA is not connected to nodeA", serviceA.nodeConnected(nodeA));
        
        serviceA.disconnectFromNode(nodeA);
        final AtomicReference<Exception> exception = new AtomicReference<>();