Sink sink = mapper.readValue(localFileSinkSpec, new TypeReference<Sink>(){});
sink.open();
Thread.sleep(1000); // wait until thread starts
assertNull(sink.recvNotice());
when(spaceChecker.hasEnoughSpace()).thenReturn(true);
for (Message m : new MessageSetReader(TestConnectionPool.createMessageSet(10000))) {
sink.writeTo(new StringMessage(m));