@InvokeOnHeader(Web3jConstants.ETH_GET_BALANCE)
    void ethGetBalance(Message message) throws IOException {
        String address = message.getHeader(Web3jConstants.ADDRESS, configuration::getAddress, String.class);
        DefaultBlockParameter atBlock
                = toDefaultBlockParameter(message.getHeader(Web3jConstants.AT_BLOCK, configuration::getAtBlock, String.class));

        Request<?, EthGetBalance> request = web3j.ethGetBalance(address, atBlock);
        setRequestId(message, request);
        EthGetBalance response = request.send();
        boolean hasError = checkForError(message, response);
        if (!hasError) {
            message.setBody(response.getBalance());
        }
    }
@Test
    public void ethGetBalanceTest() throws Exception {
        EthGetBalance response = Mockito.mock(EthGetBalance.class);
        Mockito.when(mockWeb3j.ethGetBalance(any(), any())).thenReturn(request);
        Mockito.when(request.send()).thenReturn(response);
        Mockito.when(response.getBalance()).thenReturn(BigInteger.ONE);

        Exchange exchange = createExchangeWithBodyAndHeader(null, OPERATION, Web3jConstants.ETH_GET_BALANCE);
        exchange.getIn().setHeader(Web3jConstants.AT_BLOCK, DefaultBlockParameterName.EARLIEST);

        template.send(exchange);
        BigInteger body = exchange.getIn().getBody(BigInteger.class);
        assertEquals(BigInteger.ONE, body);
    }