String equivalenceIndexLocation = asPath(
equivalenceHeaderFile.getParent(), "equivalence.index");
if (!new File(equivalenceIndexLocation).exists()) {
Indexer equivalenceIndexer = new Indexer();
equivalenceIndexer.indexEquivalenceFile(characterStopOffset,
rawEquivalenceFile, equivalenceIndexLocation);
}
return new DataFileIndex(equivalenceResourceLocation,
equivalenceIndexLocation, equivalenceHeaderFile);