@InvokeOnHeader(Web3jConstants.NET_VERSION)
    void netVersion(Message message) throws IOException {
        Request<?, NetVersion> netVersionRequest = web3j.netVersion();
        setRequestId(message, netVersionRequest);
        NetVersion response = netVersionRequest.send();
        boolean hasError = checkForError(message, response);
        if (!hasError) {
            message.setBody(response.getNetVersion());
        }
    }
@Test
    public void netVersionTest() throws Exception {
        NetVersion response = Mockito.mock(NetVersion.class);
        Mockito.when(mockWeb3j.netVersion()).thenReturn(request);
        Mockito.when(request.send()).thenReturn(response);
        Mockito.when(response.getNetVersion()).thenReturn("Net-123");

        Exchange exchange = createExchangeWithBodyAndHeader(null, OPERATION, Web3jConstants.NET_VERSION);
        template.send(exchange);
        String body = exchange.getIn().getBody(String.class);
        assertTrue(body.startsWith("Net"));
    }