* making this call. If it is not sorted, the results are undefined.
   *
   * <p>If there are elements in the list which compare as equal to the key, the choice of {@link
   * KeyPresentBehavior} decides which index is returned. If no elements compare as equal to the
   * key, the choice of {@link KeyAbsentBehavior} decides which index is returned.
   *
   * <p>This method runs in log(n) time on random-access lists, which offer near-constant-time

    Set<EndpointPair<Integer>> n1IncidentEdges = graph.incidentEdges(N1);
    Set<EndpointPair<Integer>> n2IncidentEdges = graph.incidentEdges(N2);
    assertThat(graphAsMutableGraph.removeNode(N1)).isTrue();

    // The choice of the size() method to call here is arbitrary.  We assume that if any of the Set
    // methods executes the validation check, they all will, and thus we only need to test one of

  public abstract boolean equals(@CheckForNull Object object);

  /**
   * Returns a hash code for this instance.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> this class leaves the specific choice of
   * hash code unspecified, unlike the Java 8+ equivalent.
   */
  @Override
  public abstract int hashCode();

  /**
   * Returns a string representation for this instance.
   *

  public abstract boolean equals(@CheckForNull Object object);

  /**
   * Returns a hash code for this instance.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> this class leaves the specific choice of
   * hash code unspecified, unlike the Java 8+ equivalent.
   */
  @Override
  public abstract int hashCode();

  /**
   * Returns a string representation for this instance.
   *

    Set<String> e12AdjacentEdges = network.adjacentEdges(E12);
    Set<String> n12EdgesConnecting = network.edgesConnecting(N1, N2);
    assertThat(networkAsMutableNetwork.removeNode(N1)).isTrue();

    // The choice of the size() method to call here is arbitrary.  We assume that if any of the Set
    // methods executes the validation check, they all will, and thus we only need to test one of

    Set<String> e12AdjacentEdges = network.adjacentEdges(E12);
    Set<String> n12EdgesConnecting = network.edgesConnecting(N1, N2);
    assertThat(networkAsMutableNetwork.removeNode(N1)).isTrue();

    // The choice of the size() method to call here is arbitrary.  We assume that if any of the Set
    // methods executes the validation check, they all will, and thus we only need to test one of

    Set<EndpointPair<Integer>> n1IncidentEdges = graph.incidentEdges(N1);
    Set<EndpointPair<Integer>> n2IncidentEdges = graph.incidentEdges(N2);
    assertThat(graphAsMutableGraph.removeNode(N1)).isTrue();

    // The choice of the size() method to call here is arbitrary.  We assume that if any of the Set
    // methods executes the validation check, they all will, and thus we only need to test one of

    private void workOnQueue() {
      boolean interruptedDuringTask = false;
      boolean hasSetRunning = false;
      try {
        while (true) {
          synchronized (queue) {
            // Choose whether this thread will run or not after acquiring the lock on the first
            // iteration
            if (!hasSetRunning) {
              if (workerRunningState == RUNNING) {

   *
   * @deprecated If you must interoperate with a system that requires MD5, then use this method,
   *     despite its deprecation. But if you can choose your hash function, avoid MD5, which is
   *     neither fast nor secure. As of January 2017, we suggest:
   *     <ul>
   *       <li>For security:
   *           {@link Hashing#sha256} or a higher-level API.

     *
     * <ul>
     *   <li>For an empty list, it is 1 (base case).
     *   <li>When r numbers are added to a list of n-r elements, the number of permutations is
     *       increased by a factor of (n choose r).
     * </ul>
     */
    private static <E> int calculateSize(
        List<E> sortedInputList, Comparator<? super E> comparator) {
      int permutations = 1;
      int n = 1;
      int r = 1;