public Flowable<PendingTransactionNotification> newPendingTransactionsNotifications() {
        return web3jService.subscribe(
                new Request<>(
                        "eth_subscribe",
                        Arrays.asList("newPendingTransactions"),
                        web3jService,
                        EthSubscribe.class),
                "eth_unsubscribe",
                PendingTransactionNotification.class);
    }
@Test
    public void testPendingTransactionsNotifications() {
        geth.newPendingTransactionsNotifications();

        verify(webSocketClient)
                .send(
                        matches(
                                "\\{\"jsonrpc\":\"2.0\",\"method\":\"eth_subscribe\",\"params\":"
                                        + "\\[\"newPendingTransactions\"],\"id\":[0-9]{1,}}"));
    }