public int getNumOfSegments() {
    return 1;
  }
------------------------------------------------------------------------ Copy C-tor to be used
when new CSLMImmutableSegment (derived) is being built from a Mutable one. This C-tor should be
used when active MutableSegment is pushed into the compaction pipeline and becomes an
ImmutableSegment.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/ImmutableSegment.java