void setIndexType(IndexType type) {
    indexType = type;
    // Because this functionality is for testing only and tests are setting in-memory flush size
    // according to their need, there is no setting of in-memory flush size, here.
    // If it is needed, please change in-memory flush size explicitly
  }
@param requesterVersion The caller must hold the VersionedList of the pipeline with version
                        taken earlier. This version must be passed as a parameter here. The
                        flattening happens only if versions match.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/CompactingMemStore.java