@Override
  public void remove() {
    throw new UnsupportedOperationException();
  }
The MemStoreCompactorSegmentsIterator extends MemStoreSegmentsIterator and performs the scan for
compaction operation meaning it is based on SQM
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MemStoreCompactorSegmentsIterator.java