@Deprecated
  public long initialize() throws IOException {
    return initialize(null);
  }
Initialize this region. Used only by tests and SplitTransaction to reopen the region. You
should use createHRegion() or openHRegion()
@return What the next sequence (edit) id should be.
@throws IOException e
@deprecated use HRegion.createHRegion() or HRegion.openHRegion()
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java