} catch (UnsupportedOperationException e) {
        Set<K> toRemove = new HashSet<>();
        for (Entry<K, V> entry : map().entrySet()) {
          if (c.contains(entry.getValue())) {
            toRemove.add(entry.getKey());
          }
        }
        return map().keySet().removeAll(toRemove);
      }
    }

    @Override
    public boolean retainAll(Collection<?> c) {

      } catch (UnsupportedOperationException e) {
        Set<K> toRemove = new HashSet<>();
        for (Entry<K, V> entry : map().entrySet()) {
          if (c.contains(entry.getValue())) {
            toRemove.add(entry.getKey());
          }
        }
        return map().keySet().removeAll(toRemove);
      }
    }

    @Override
    public boolean retainAll(Collection<?> c) {

		delete(foundDirs, dir)
	}

	// Delete excessive directories.
	// Do not abort on context errors.
	for dir := range foundDirs {
		toRemove := pathJoin(volumeDir, path, dir+SlashSeparator)
		err = s.deleteFile(volumeDir, toRemove, true, true)
		diskHealthCheckOK(ctx, err)
		if err != nil {
			return err
		}
	}

	// Do the same for inline data
	dirs, err := xl.data.list()