private Writer generateWALs(int leaveOpen) throws IOException {
    return generateWALs(NUM_WRITERS, ENTRIES, leaveOpen, 0);
  }
See HBASE-27644, typically we should not have empty WALEdit but we should be able to process
it, instead of losing data after it.
hbase-server/src/test/java/org/apache/hadoop/hbase/wal/TestWALSplit.java