* - Under Java 9+, createTempDir() succeeds because it can look up the *real* username, rather
     * than relying on the one from the system property.
     *
     * - Under Java 8, createTempDir() fails because it falls back to the bogus username from the
     * system property.
     */

    String save = System.getProperty("user.name");
    System.setProperty("user.name", "-this-is-definitely-not-the-username-we-are-running-as//?");
    try {

   * To avoid the need to call requireNonNull so much, we could consider more clever approaches,
   * such as:
   *
   * - Make checkOpen return the non-null `seq`. Then callers can assign that to a local variable or
   *   even back to `this.seq`. However, that may suggest that we're defending against concurrent
   *   mutation, which is not an actual risk because we use `synchronized`.

    public <T> T[] toArray(T[] array) {
      return snapshot().toArray(array);
    }

    /*
     * We'd love to use 'new ArrayList(this)' or 'list.addAll(this)', but
     * either of these would recurse back to us again!
     */
    private List<E> snapshot() {
      List<E> list = Lists.newArrayListWithExpectedSize(size());
      for (Multiset.Entry<E> entry : entrySet()) {
        E element = entry.getElement();

    // Now process directly from the rest of the input buffer
    while (readBuffer.remaining() >= chunkSize) {
      process(readBuffer);
    }

    // Finally stick the remainder back in our usual buffer
    buffer.put(readBuffer);
    return this;
  }

  /*
   * Note: hashString(CharSequence, Charset) is intentionally not overridden.
   *

   *
   * @return the fully constructed {@link ThreadFactory}
   */
  public ThreadFactory build() {
    return doBuild(this);
  }

  // Split out so that the anonymous ThreadFactory can't contain a reference back to the builder.
  // At least, I assume that's why. TODO(cpovirk): Check, and maybe add a test for this.
  private static ThreadFactory doBuild(ThreadFactoryBuilder builder) {
    String nameFormat = builder.nameFormat;

  public <T extends @Nullable Object> T[] toArray(T[] array) {
    return snapshot().toArray(array);
  }

  /*
   * We'd love to use 'new ArrayList(this)' or 'list.addAll(this)', but
   * either of these would recurse back to us again!
   */
  private List<E> snapshot() {
    List<E> list = Lists.newArrayListWithExpectedSize(size());
    for (Multiset.Entry<E> entry : entrySet()) {
      E element = entry.getElement();

   * expectedCapacity)) rather than O(calls to add).
   *
   * <p>This implementation attempts to detect hash flooding, and if it's identified, falls back to
   * JdkBackedSetBuilderImpl.
   */
  private static final class RegularSetBuilderImpl<E> extends SetBuilderImpl<E> {
    // null until at least two elements are present

import java.util.Iterator;
import javax.annotation.CheckForNull;

/**
 * A function from {@code A} to {@code B} with an associated <i>reverse</i> function from {@code B}
 * to {@code A}; used for converting back and forth between <i>different representations of the same
 * information</i>.
 *
 * <h3>Invertibility</h3>
 *
 * <p>The reverse operation <b>may</b> be a strict <i>inverse</i> (meaning that {@code

            cells = rs;
            init = true;
          }
        } finally {
          busy = 0;
        }
        if (init) break;
      } else if (casBase(v = base, fn(v, x))) break; // Fall back on using base
    }
  }

  /** Sets base and all cells to the given value. */
  final void internalReset(long initialValue) {
    Cell[] as = cells;
    base = initialValue;
    if (as != null) {

    assertEquals((Integer) 30, it.next());
    assertEquals((Integer) 40, it.next());
    // Skipping 20
    assertEquals((Integer) 11, it.next());
    // Not skipping 400, because it moved back down
    assertEquals((Integer) 400, it.next());
    assertEquals((Integer) 13, it.next());
    assertEquals((Integer) 200, it.next());
    assertEquals((Integer) 300, it.next());
    // Last from forgetMeNot.