private static <T> boolean containsAll(final Collection<? extends T> collection, Iterable<? extends T> it) {
    if (collection == null || collection.isEmpty()) {
      return false;
    }
    for (T file : it) {
      if (!collection.contains(file)) {
        return false;
      }
    }
    return true;
  }
private static <T> boolean containsAll(final Collection<? extends T> collection, Iterable<? extends T> it)