public void advanceTo(long newStartPoint) {
    while (true) {
      long seqId = this.getWritePoint();
      if (seqId >= newStartPoint) {
        break;
      }
      if (this.tryAdvanceTo(newStartPoint, seqId)) {
        break;
      }
    }
  }
Step the MVCC forward on to a new read/write basis.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MultiVersionConcurrencyControl.java