}
  }

  /**
   * Returns the set of all possible subsets of {@code set}. For example, {@code
   * powerSet(ImmutableSet.of(1, 2))} returns the set {@code {{}, {1}, {2}, {1, 2}}}.
   *
   * <p>Elements appear in these subsets in the same iteration order as they appeared in the input
   * set. The order in which these subsets appear in the outer set is undefined. Note that the power

    }

    @Override
    public NavigableSet<E> subSet(
        E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
      synchronized (mutex) {
        return Synchronized.navigableSet(
            delegate().subSet(fromElement, fromInclusive, toElement, toInclusive), mutex);
      }
    }

    @Override
    public SortedSet<E> subSet(E fromElement, E toElement) {

    }

    @Override
    public NavigableSet<E> subSet(
        E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
      synchronized (mutex) {
        return Synchronized.navigableSet(
            delegate().subSet(fromElement, fromInclusive, toElement, toInclusive), mutex);
      }
    }

    @Override
    public SortedSet<E> subSet(E fromElement, E toElement) {

		if err != nil {
			return np, grid.NewRemoteErr(err)
		}
		subSys := vars.Get(peerRESTSubSys)
		// Apply dynamic values.
		ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
		defer cancel()
		if subSys == "" {
			err = applyDynamicConfig(ctx, objAPI, srvCfg)
		} else {
			err = applyDynamicConfigForSubSys(ctx, objAPI, srvCfg, subSys)
		}
		if err != nil {
			return np, grid.NewRemoteErr(err)

                problems.add(
                        0,
                        new DefaultModelProblem(
                                "Too many model problems reported (listed problems are just a subset of reported problems)",
                                org.apache.maven.model.building.ModelProblem.Severity.WARNING,
                                null,
                                null,

     */
    @Nullable V get();

    /** Returns the entry which contains this {@link WeakValueReference}. */
    E getEntry();

    /** Unsets the referenced value. Subsequent calls to {@link #get} will return {@code null}. */
    void clear();

    /**
     * Returns a freshly created {@link WeakValueReference} for the given {@code entry} (and on the