### Question:
SimpleRpcListener extends AbstractRpcListener<Void> { @Override protected void operationSuccessful() { successfulRpc(null); } SimpleRpcListener(final Object message, final String failureInfo);   }### Answer:
@Test public void testSuccessfulRpc() { SimpleRpcListener listener = new SimpleRpcListener("MESSAGE", "Failed to send message"); listener.operationSuccessful(); SettableFuture<RpcResult<?>> result = SettableFuture.create(); result.set(RpcResultBuilder.success((Void)null).build()); try { Assert.assertEquals("Wrong result", result.get().getErrors(), listener.getResult().get().getErrors()); Assert.assertEquals("Wrong result", result.get().getResult(), listener.getResult().get().getResult()); Assert.assertEquals("Wrong result", result.get().isSuccessful(), listener.getResult().get().isSuccessful()); } catch (InterruptedException | ExecutionException e) { fail("Problem accessing result"); } }