private void ensureLevel0Metadata(HStoreFile sf) {
    if (!isInvalid(startOf(sf))) this.fileStarts.put(sf, INVALID_KEY_IN_MAP);
    if (!isInvalid(endOf(sf))) this.fileEnds.put(sf, INVALID_KEY_IN_MAP);
  }
Loads initial store files that were picked up from some physical location pertaining to this
store (presumably). Unlike adding files after compaction, assumes empty initial sets, and is
forgiving with regard to stripe constraints - at worst, many/all files will go to level 0.
@param storeFiles Store files to add.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StripeStoreFileManager.java