*/
static Path split(final FileSystem fs, final Path splitDir,
final StoreFile f, final byte [] splitRow, final Reference.Range range)
throws IOException {
// A reference to the bottom half of the hsf store file.
Reference r = new Reference(splitRow, range);
// Add the referred-to regions name as a dot separated suffix.
// See REF_NAME_PARSER regex above. The referred-to regions name is
// up in the path of the passed in <code>f</code> -- parentdir is family,
// then the directory above is the region name.
String parentRegionName = f.getPath().getParent().getParent().getName();
// Write reference with same file id only with the other region name as
// suffix and into the new region location (under same family).
Path p = new Path(splitDir, f.getPath().getName() + "." + parentRegionName);
return r.write(fs, p);
}