@Override
      public boolean evaluate() throws Exception {
        return fs.getFileStatus(walPath).getLen() > 0
          && ((AbstractFSWAL<?>) log).getInflightWALCloseCount() == 0;
      }
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