* null will be returned.
   *
   * @throws ParameterNotInstantiableException if the static methods cannot be invoked because the
   *     default value of a parameter cannot be determined.
   * @throws IllegalAccessException if the class isn't public or is nested inside a non-public
   *     class, preventing its methods from being accessible.
   * @throws InvocationTargetException if a static method threw exception.
   */

   * that this throws different exception types, and throws an exception if {@code null} would be
   * returned).
   *
   * @param position position of the element to return
   * @return the element at the specified position in this fluent iterable
   * @throws IndexOutOfBoundsException if {@code position} is negative or greater than or equal to

   * that this throws different exception types, and throws an exception if {@code null} would be
   * returned).
   *
   * @param position position of the element to return
   * @return the element at the specified position in this fluent iterable
   * @throws IndexOutOfBoundsException if {@code position} is negative or greater than or equal to

   */
  @Test
  public void testNulls() throws Exception {
    for (Class<?> classToTest : findClassesToTest(loadClassesInPackage(), NULL_TEST_METHOD_NAMES)) {
      if (classToTest.getSimpleName().equals("ReflectionFreeAssertThrows")) {
        /*
         * These classes handle null properly but throw IllegalArgumentException for the default

   */
  @Test
  public void testNulls() throws Exception {
    for (Class<?> classToTest : findClassesToTest(loadClassesInPackage(), NULL_TEST_METHOD_NAMES)) {
      if (classToTest.getSimpleName().equals("ReflectionFreeAssertThrows")) {
        /*
         * These classes handle null properly but throw IllegalArgumentException for the default

    return this;
  }

  /**
   * Specifies the expected number of nodes in the graph.
   *
   * @throws IllegalArgumentException if {@code expectedNodeCount} is negative
   */
  @CanIgnoreReturnValue
  public ValueGraphBuilder<N, V> expectedNodeCount(int expectedNodeCount) {
    this.expectedNodeCount = checkNonNegative(expectedNodeCount);
    return this;
  }

  /**

    return this;
  }

  /**
   * Specifies the expected number of nodes in the network.
   *
   * @throws IllegalArgumentException if {@code expectedNodeCount} is negative
   */
  @CanIgnoreReturnValue
  public NetworkBuilder<N, E> expectedNodeCount(int expectedNodeCount) {
    this.expectedNodeCount = checkNonNegative(expectedNodeCount);
    return this;
  }

  /**

    return this;
  }

  /**
   * Specifies the expected number of nodes in the graph.
   *
   * @throws IllegalArgumentException if {@code expectedNodeCount} is negative
   */
  @CanIgnoreReturnValue
  public GraphBuilder<N> expectedNodeCount(int expectedNodeCount) {
    this.expectedNodeCount = checkNonNegative(expectedNodeCount);
    return this;
  }

  /**

    if (connections == null) {
      checkNotNull(node);
      throw new IllegalArgumentException(String.format(NODE_NOT_IN_GRAPH, node));
    }
    return connections;
  }

  final N checkedReferenceNode(E edge) {
    N referenceNode = edgeToReferenceNode.get(edge);
    if (referenceNode == null) {
      checkNotNull(edge);
      throw new IllegalArgumentException(String.format(EDGE_NOT_IN_GRAPH, edge));
    }

  }

  private final GraphConnections<N, V> checkedConnections(N node) {
    GraphConnections<N, V> connections = nodeConnections.get(node);
    if (connections == null) {
      checkNotNull(node);
      throw new IllegalArgumentException("Node " + node + " is not an element of this graph.");
    }
    return connections;
  }

  final boolean containsNode(@Nullable N node) {
    return nodeConnections.containsKey(node);