@Override
    public boolean ensureFolder(@NonNull final Folder folder, final boolean needsWrite) throws IOException {
        try {
            //we have to validate cache for this one, otherwise outdated entries may lead to a false-positive
            return getFolderUri(folder, needsWrite, true, true) != null;
        } catch (IllegalArgumentException iae) {
            Log.w("Problem ensuring folder '" + folder + "' nw=" + needsWrite, iae);
            return false;
        }
    }
retrieves a FileInformation object from the current cursor row retrieved by using {@link #queryDir(Uri, String[], Func1)} columns
main/src/main/java/cgeo/geocaching/storage/DocumentContentAccessor.java