@Override
    public String sendCall(String to, String data, DefaultBlockParameter defaultBlockParameter)
            throws IOException {
        EthCall ethCall =
                web3j.ethCall(
                                Transaction.createEthCallTransaction(fromAddress, to, data),
                                defaultBlockParameter)
                        .send();

        assertCallNotReverted(ethCall);
        return ethCall.getValue();
    }
@Test
    public void sendCallTest() throws IOException {
        when(response.getValue()).thenReturn("test");
        when(service.send(any(), any())).thenReturn(response);
        ReadonlyTransactionManager readonlyTransactionManager =
                new ReadonlyTransactionManager(web3j, "");
        String value = readonlyTransactionManager.sendCall("", "", defaultBlockParameter);
        assertEquals("test", value);
    }