code: public static void writeHash(File file, HashType hashType) throws IOException {
      SparkeyWriter writer = append(file);
      writer.writeHash(hashType);
      writer.close();
    }
docs: Write (or rewrite) the index file for a given sparkey file.
  
  @param file File base to use, the actual file endings will be set to .spi and .spl
  @param hashType choice of hash type, can be 32 or 64 bits.