* IllegalArgumentException}.
   */
  @Override
  boolean allowsSelfLoops();

  /** Returns the order of iteration for the elements of {@link #nodes()}. */
  @Override
  ElementOrder<N> nodeOrder();

  /**
   * Returns an {@link ElementOrder} that specifies the order of iteration for the elements of
   * {@link #edges()}, {@link #adjacentNodes(Object)}, {@link #predecessors(Object)}, {@link

   * whose keys and values are the result of applying the provided mapping functions to the input
   * elements.
   *
   * <p>For streams with defined encounter order (as defined in the Ordering section of the {@link
   * java.util.stream} Javadoc), that order is preserved, but entries are <a
   * href="ImmutableMultimap.html#iteration">grouped by key</a>.
   *
   * <p>Example:
   *
   * <pre>{@code

    addNodes(graph);

    assertThat(graph.nodeOrder())
        .isEqualTo(ElementOrder.sorted(Ordering.<Integer>natural().reverse()));
    assertThat(graph.nodes()).containsExactly(4, 3, 1).inOrder();
  }

  // Edge order tests

  @Test
  public void edgeOrder_none() {
    MutableNetwork<Integer, String> network =
        NetworkBuilder.directed().edgeOrder(unordered()).build();

------------------

Get working code on a personal branch with tests passing before you submit a PR:

```
./gradlew clean check
```

Please make every effort to follow existing conventions and style in order to keep the code as
readable as possible.

Contribute code changes through GitHub by forking the repository and sending a pull request. We
squash all pull requests on merge.


Gradle Setup
------------

```

------------------

Get working code on a personal branch with tests passing before you submit a PR:

```
./gradlew clean check
```

Please make every effort to follow existing conventions and style in order to keep the code as
readable as possible.

Contribute code changes through GitHub by forking the repository and sending a pull request. We
squash all pull requests on merge.


Gradle Setup
------------

```

    ByteBuffer littleEndian = ByteBuffer.wrap(bytes).order(ByteOrder.LITTLE_ENDIAN);
    ByteBuffer bigEndian = ByteBuffer.wrap(bytes).order(ByteOrder.BIG_ENDIAN);
    assertEquals(hashFunction.hashBytes(littleEndian), hashFunction.hashBytes(bigEndian));
    assertEquals(ByteOrder.LITTLE_ENDIAN, littleEndian.order());
    assertEquals(ByteOrder.BIG_ENDIAN, bigEndian.order());
  }

  V forcePut(@ParametricNullness K key, @ParametricNullness V value);

  // Bulk Operations

  /**
   * {@inheritDoc}
   *
   * <p><b>Warning:</b> the results of calling this method may vary depending on the iteration order
   * of {@code map}.
   *
   * @throws IllegalArgumentException if an attempt to {@code put} any entry fails. Note that some
   *     map entries may have been added to the bimap before the exception was thrown.
   */

            EndpointPair.unordered(1, 1),
            EndpointPair.unordered(1, 3))
        .inOrder();
  }

  /**
   * Populates the graph with nodes and edges in a star shape with node `1` in the middle.
   *
   * <p>Note that the edges are added in a shuffled order to properly test the effect of the
   * insertion order.
   */
  private void populateTShapedGraph() {
    putEdge(2, 1);
    putEdge(1, 4);

        // The hardware is big-endian, so we need to reverse the order of the bytes.
        return Long.reverseBytes(bigEndian);
      }

      @Override
      public void putLongLittleEndian(byte[] array, int offset, long value) {
        // Reverse the order of the bytes before storing, since we're on big-endian hardware.
        long littleEndianValue = Long.reverseBytes(value);

    protected SortedSet<Integer> create(Integer[] elements) {
      return checkedCreate(nullCheckedTreeSet(elements)).descendingSet();
    }

    /** Sorts the elements in reverse natural order. */
    @Override
    public List<Integer> order(List<Integer> insertionOrder) {
      sort(insertionOrder, Ordering.<Integer>natural().reverse());
      return insertionOrder;
    }
  }