* element, or at the end of the list if {@code nextSibling} is null. Note: if {@code nextSibling}
   * is specified, it MUST be for a node for the same {@code key}!
   */
  @CanIgnoreReturnValue
  private Node<K, V> addNode(
      @ParametricNullness K key,
      @ParametricNullness V value,
      @CheckForNull Node<K, V> nextSibling) {
    Node<K, V> node = new Node<>(key, value);
    if (head == null) { // empty list

  StandardMutableNetwork(NetworkBuilder<? super N, ? super E> builder) {
    super(builder);
  }

  @Override
  @CanIgnoreReturnValue
  public boolean addNode(N node) {
    checkNotNull(node, "node");

    if (containsNode(node)) {
      return false;
    }

    addNodeInternal(node);
    return true;
  }

  /**

                stream(baseTags).of(stream -> stream.forEach(tag -> popularWordsRequestBuilder.addTag(tag)));
                stream(baseRoles).of(stream -> stream.forEach(role -> popularWordsRequestBuilder.addRole(role)));
                stream(baseFields).of(stream -> stream.forEach(field -> popularWordsRequestBuilder.addField(field)));

        SuggestItem[] items = getItemSet1();
        suggester.indexer().index(items);
        suggester.refresh();

        SuggestResponse response = suggester.suggest().setQuery("kensaku").addRole("role1").setSuggestDetail(true).execute().getResponse();
        assertEquals(1, response.getNum());
        assertEquals("検索 エンジン", response.getWords().get(0));

        suggester.indexer().delete(items[0].getId());

    }

    public void setQuery(final String query) {
        this.query = query;
    }

    public void addTag(final String tag) {
        tags.add(tag);
    }

    public void addRole(final String role) {
        roles.add(role);
    }

    public void addField(final String field) {
        fields.add(field);
    }

    public void addKind(final String kind) {
        kinds.add(kind);

    MutableGraph<Integer> directedGraph = GraphBuilder.directed().allowsSelfLoops(false).build();
    directedGraph.putEdge(N1, N2);
    directedGraph.putEdge(N1, N3);
    directedGraph.putEdge(N2, N3);
    directedGraph.addNode(N4);

    MutableGraph<Integer> expectedClosure = GraphBuilder.directed().allowsSelfLoops(true).build();
    expectedClosure.putEdge(N1, N1);
    expectedClosure.putEdge(N1, N2);
    expectedClosure.putEdge(N1, N3);

      ImmutableDoubleArray iia = builder.build();
      for (int j = 0; j < iia.length(); j++) {
        assertThat(iia.get(j)).isEqualTo((double) j);
      }
    }
  }

  private enum BuilderOp {
    ADD_ONE {
      @Override
      void doIt(ImmutableDoubleArray.Builder builder, AtomicInteger counter) {
        builder.add(counter.getAndIncrement());
      }
    },
    ADD_ARRAY {
      @Override

      }
      ImmutableIntArray iia = builder.build();
      for (int j = 0; j < iia.length(); j++) {
        assertThat(iia.get(j)).isEqualTo(j);
      }
    }
  }

  private enum BuilderOp {
    ADD_ONE {
      @Override
      void doIt(ImmutableIntArray.Builder builder, AtomicInteger counter) {
        builder.add(counter.getAndIncrement());
      }
    },
    ADD_ARRAY {
      @Override

      ImmutableDoubleArray iia = builder.build();
      for (int j = 0; j < iia.length(); j++) {
        assertThat(iia.get(j)).isEqualTo((double) j);
      }
    }
  }

  private enum BuilderOp {
    ADD_ONE {
      @Override
      void doIt(ImmutableDoubleArray.Builder builder, AtomicInteger counter) {
        builder.add(counter.getAndIncrement());
      }
    },
    ADD_ARRAY {
      @Override

            stream(parameter.getSuggestFields()).of(stream -> stream.forEach(builder::addField));
            roleQueryHelper.build(SearchRequestType.SUGGEST).stream().forEach(builder::addRole);
            builder.setSize(parameter.getNum());
            stream(langs).of(stream -> stream.forEach(builder::addLang));

            stream(parameter.getTags()).of(stream -> stream.forEach(builder::addTag));