public async Task TestCallCommand()
        {
            var msg = await client.Call(new CallMessage("blockchain.address.get_history",
                                                        new[] { "mrx4EmF6zHXky3zDoeJ1K7KvYcuNn8Mmc4" }));

            Assert.AreEqual(msg.Result[0].Value <string>("tx_hash"),
                            "3aa2a5a9825ca767e092bcc19487aa13969eeb217fd0fba8492543bbb8c30954");
            Assert.AreEqual(msg.Result[0].Value <int>("height"), 260144);
        }