* current implementations, the iteration order always keeps multiple entries with the same key
 * together. Any creation method that would customarily respect insertion order (such as {@link
 * #copyOf(Multimap)}) instead preserves key-grouped order by inserting entries for an existing key
 * immediately after the last entry having that key.
 *
 * <p>See the Guava User Guide article on <a href=

                    )

                    async def _keepalive_inserter() -> None:
                        """Read from the producer and forward to the output,
                        inserting keepalive comments on timeout."""
                        async with send_keepalive, receive_stream:
                            try:
                                while True:
                                    try:

   */
  public long approximateElementCount() {
    long bitSize = bits.bitSize();
    long bitCount = bits.bitCount();

    /*
     * Each insertion is expected to reduce the # of clear bits by a factor of
     * `numHashFunctions/bitSize`. So, after n insertions, expected bitCount is `bitSize * (1 - (1 -
     * numHashFunctions/bitSize)^n)`. Solving that for n, and approximating `ln x` as `x - 1` when x

   *         <li>{@code edges()}: Stable order
   *         <li>{@code adjacentNodes(node)}: Connecting edge insertion order
   *         <li>{@code predecessors(node)}: Connecting edge insertion order
   *         <li>{@code successors(node)}: Connecting edge insertion order
   *         <li>{@code incidentEdges(node)}: Edge insertion order
   *       </ul>
   *   <li>For {@link Network}:
   *       <ul>

  @Test
  public void nodeOrder_insertion() {
    MutableGraph<Integer> graph = GraphBuilder.directed().nodeOrder(insertion()).build();

    addNodes(graph);

    assertThat(graph.nodeOrder()).isEqualTo(insertion());
    assertThat(graph.nodes()).containsExactly(3, 1, 4).inOrder();
  }

  // The default ordering is INSERTION unless otherwise specified.
  @Test
  public void nodeOrder_default() {

   * specified access policy.
   *
   * @param capacity the capacity of this queue
   * @param fair if {@code true} then queue accesses for threads blocked on insertion or removal,
   *     are processed in FIFO order; if {@code false} the access order is unspecified.
   * @throws IllegalArgumentException if {@code capacity} is less than 1
   */

    return this;
  }

  /**
   * Specifies the order of iteration for the elements of {@link Network#nodes()}.
   *
   * <p>The default value is {@link ElementOrder#insertion() insertion order}.
   */
  public <N1 extends N> NetworkBuilder<N1, E> nodeOrder(ElementOrder<N1> nodeOrder) {
    NetworkBuilder<N1, E> newBuilder = cast();
    newBuilder.nodeOrder = checkNotNull(nodeOrder);

  private transient int[] nextInBucketVToK;

  /** The "entry" of the first element in insertion order. */
  private transient int firstInInsertionOrder;

  /** The "entry" of the last element in insertion order. */
  private transient int lastInInsertionOrder;

  /** Maps an "entry" to the "entry" that precedes it in insertion order. */
  private transient int[] prevInInsertionOrder;

  private enum InsertionOrder {
    FRONT {
      @Override
      <T> void insertInto(Deque<T> deque, T value) {
        deque.addFirst(value);
      }
    },
    BACK {
      @Override
      <T> void insertInto(Deque<T> deque, T value) {
        deque.addLast(value);
      }
    };

    abstract <T> void insertInto(Deque<T> deque, T value);
  }

    return this;
  }

  /**
   * Specifies the order of iteration for the elements of {@link Graph#nodes()}.
   *
   * <p>The default value is {@link ElementOrder#insertion() insertion order}.
   */
  public <N1 extends N> GraphBuilder<N1> nodeOrder(ElementOrder<N1> nodeOrder) {
    GraphBuilder<N1> newBuilder = cast();
    newBuilder.nodeOrder = checkNotNull(nodeOrder);
    return newBuilder;