Refactor `AbstractSimpleTransportTestCase` and `MockTransportService` to not use `Version.transportVersion` 
test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java
fail("got exception instead of a response: " + exp.getMessage());
                }
            }
        ).get();
        assertThat(version0Response.value1, equalTo(1));
    }
    public void testVersionFrom1to0() throws Exception {
        serviceA.registerRequestHandler("internal:version", ThreadPool.Names.SAME, Version0Request::new, (request, channel, task) -> {
            assertThat(request.value1, equalTo(1));
            Version0Response response = new Version0Response(1);
            channel.sendResponse(response);
            assertEquals(version0.transportVersion, channel.getVersion());
        });
        Version1Request version1Request = new Version1Request();
        version1Request.value1 = 1;
        version1Request.value2 = 2;
        Version1Response version1Response = submitRequest(
            serviceB,
            nodeA,
            "internal:version",
            version1Request,
            new TransportResponseHandler<Version1Response>() {
                @Override
                public Version1Response read(StreamInput in) throws IOException {
                    return new Version1Response(in);
                }
                @Override
                public void handleResponse(Version1Response response) {
                    assertThat(response.value1, equalTo(1));
                    assertThat(response.value2, equalTo(0));