public Uri rename(final Uri uri, final FileNameCreator fileNameCreator) {
        if (isEmpty(uri)) {
            return null;
        }

        try {
            return getAccessorFor(uri).rename(uri, fileNameCreator.createName());
        } catch (IOException ioe) {
            reportProblem(R.string.contentstorage_err_delete_failed, ioe, false, uri);
        }
        return null;
    }
Renames the file represented by given Uri. This might change the Uri, the new Uri is returned.
If rename is unsuccessful then null is returned
main/src/main/java/cgeo/geocaching/storage/ContentStorage.java