code: @Override
  	public void close() throws IOException {
  		if (! closed) {
  			LOGGER.debug("Wall clock for quicksort: " + Util.format(quickSortWallTime / 1E9) + "s");
  			closed = true;
  			for(final WritableByteChannel channel: writableByteChannel) channel.close();
  			for(final File f: file) f.delete();
  		}
  	}
docs: Closes this store, disposing all associated resources.