File tmpdir = FileUtil.mktempdir();
TailDirSource src = new TailDirSource(tmpdir, "foo.*");
AccumulatorSink cnt = new AccumulatorSink("tailcount");
DirectDriver drv = new DirectDriver(src, cnt);
drv.start();
Clock.sleep(1000);
genFiles(tmpdir, "foo", 10, 100);
genFiles(tmpdir, "bar", 15, 100);