@RestrictedApi(explanation = "Should only be called in tests", link = "",
      allowedOnPath = ".*/src/test/.*")
  public SequenceIdAccounting getSequenceIdAccounting() {
    return sequenceIdAccounting;
  }
Used to initialize the WAL. Usually just call rollWriter to create the first log writer.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/AbstractFSWAL.java