private boolean treeWalk(final Folder root, final boolean ordered, final Func1<ImmutablePair<ContentStorage.FileInformation, Boolean>, TreeWalkResult> callback) {
        return treeWalkRecursive(root, ordered, callback) == TreeWalkResult.CONTINUE;
    }
Returns a pair of longs where left one is free space in bytes and right one is number of files
main/src/main/java/cgeo/geocaching/storage/FolderUtils.java