@Test
  public void testEmptyStream() throws Exception {
    try (WALEntryStream entryStream =
      new WALEntryStream(logQueue, fs, CONF, 0, log, new MetricsSource("1"), fakeWalGroupId)) {
      assertEquals(HasNext.RETRY, entryStream.hasNext());
    }
  }
Tests that if we stop before hitting the end of a stream, we can continue where we left off
using the last position
hbase-server/src/test/java/org/apache/hadoop/hbase/replication/regionserver/TestBasicWALEntryStream.java