private String extractGroupId(PlexusConfiguration c) {
        return c.getChild("groupId").getValue();
    }

    private String extractArtifactId(PlexusConfiguration c) {
        return c.getChild("artifactId").getValue();
    }

    private String extractVersion(PlexusConfiguration c) {
        return c.getChild("version").getValue();
    }

    private String extractGoalPrefix(PlexusConfiguration c) {

  }

  protected final V v0() {
    return e0().getValue();
  }

  protected final K k1() {
    return e1().getKey();
  }

  protected final V v1() {
    return e1().getValue();
  }

  protected final K k2() {
    return e2().getKey();
  }

  protected final V v2() {
    return e2().getValue();
  }

  protected final K k3() {
    return e3().getKey();

    assertEqualIgnoringOrder(getMap().inverse().entrySet(), reversedEntries);

    for (Entry<K, V> entry : expected) {
      assertEquals(
          "Wrong key for value " + entry.getValue(),
          entry.getKey(),
          getMap().inverse().get(entry.getValue()));
    }
  }

  @Override
  protected void expectMissing(Entry<K, V>... entries) {
    super.expectMissing(entries);
    for (Entry<K, V> entry : entries) {

      this.samples =
          new SampleElements<>(
              mapSamples.e0().getValue(),
              mapSamples.e1().getValue(),
              mapSamples.e2().getValue(),
              mapSamples.e3().getValue(),
              mapSamples.e4().getValue());
    }

    @Override
    public SampleElements<V> samples() {
      return samples;
    }

    @Override

      Range<K> range, V value, @CheckForNull Entry<Cut<K>, RangeMapEntry<K, V>> entry) {
    if (entry != null
        && entry.getValue().getKey().isConnected(range)
        && entry.getValue().getValue().equals(value)) {
      return range.span(entry.getValue().getKey());
    }
    return range;
  }

  @Override
  public void putAll(RangeMap<K, ? extends V> rangeMap) {

            assertEquals("lib/tools.jar", config0.getChild("toolsJar").getValue());
            assertEquals(2, config0.getChildCount());
            Xpp3Dom config1 = (Xpp3Dom) jdks.getToolchains().get(1).getConfiguration();
            assertEquals(2, config1.getChildCount());
            assertEquals("lib/classes.jar", config1.getChild("toolsJar").getValue());
            assertEquals(2, jdksExtend.getToolchains().size());
        }

      Range<K> range, V value, @CheckForNull Entry<Cut<K>, RangeMapEntry<K, V>> entry) {
    if (entry != null
        && entry.getValue().getKey().isConnected(range)
        && entry.getValue().getValue().equals(value)) {
      return range.span(entry.getValue().getKey());
    }
    return range;
  }

  @Override
  public void putAll(RangeMap<K, ? extends V> rangeMap) {

      K key = entry.getKey();
      Collection<V> collection = filterCollection(entry.getValue(), new ValuePredicate(key));
      if (!collection.isEmpty()
          && predicate.apply(Maps.<K, Collection<V>>immutableEntry(key, collection))) {
        if (collection.size() == entry.getValue().size()) {
          entryIterator.remove();
        } else {
          collection.clear();
        }

  }

  protected final V v0() {
    return e0().getValue();
  }

  protected final K k1() {
    return e1().getKey();
  }

  protected final V v1() {
    return e1().getValue();
  }

  protected final K k2() {
    return e2().getKey();
  }

  protected final V v2() {
    return e2().getValue();
  }

  protected final K k3() {
    return e3().getKey();

      this.samples =
          new SampleElements<>(
              mapSamples.e0().getValue(),
              mapSamples.e1().getValue(),
              mapSamples.e2().getValue(),
              mapSamples.e3().getValue(),
              mapSamples.e4().getValue());
    }

    @Override
    public SampleElements<V> samples() {
      return samples;
    }

    @Override