@Test
  public void testHeartbeat() throws IOException, InterruptedException, ExecutionException {
    Path f = new Path("/" + name.getMethodName());
    EventLoop eventLoop = EVENT_LOOP_GROUP.next();
    FanOutOneBlockAsyncDFSOutput out = FanOutOneBlockAsyncDFSOutputHelper.createOutput(FS, f, true,
      false, (short) 3, FS.getDefaultBlockSize(), eventLoop, CHANNEL_CLASS, MONITOR, true);
    Thread.sleep(READ_TIMEOUT_MS * 2);
    // the connection to datanode should still alive.
    writeAndVerify(FS, f, out);
  }
Test method has been renamed to be the first in NAME_ASCENDING. It's an ugly hack to avoid
flakiness.
hbase-asyncfs/src/test/java/org/apache/hadoop/hbase/io/asyncfs/TestFanOutOneBlockAsyncDFSOutput.java