public T send() throws IOException {
        return web3jService.send(this, responseType);
    }
@Test
    public void testEthFeeHistory() throws Exception {
        web3j.ethFeeHistory(1, DefaultBlockParameterName.LATEST, null).send();

        verifyResult(
                "{\"jsonrpc\":\"2.0\",\"method\":\"eth_feeHistory\",\"params\":[\"0x1\",\"latest\",null],\"id\":1}");
    }