pub fn walk_for_presets(
roots: &[PathBuf],
on_batch: &mut dyn FnMut(&[PresetFile], usize),
should_stop: &(dyn Fn() -> bool + Sync),
exclude: Option<HashSet<String>>,
active_dirs: Option<Arc<Mutex<Vec<String>>>>,
incremental: Option<Arc<IncrementalDirState>>,
)