invalidate method
Implementation
void invalidate([String? path]) {
if (path == null) {
_cache.clear();
_childrenCache.clear();
verbose("INVAL **");
} else {
_cache.removeWhere((k, i) => VPaths.contains(path, k));
_childrenCache.removeWhere((k, i) => VPaths.contains(path, k));
verbose("INVAL $path");
}
}