Long.MIN_VALUE,
            Long.MAX_VALUE)) {
      for (double delta : Doubles.asList(0.0, 1.0, 2.0)) {
        integralBuilder.addAll(Doubles.asList(d + delta, d - delta, -d - delta, -d + delta));
      }
      for (double delta : Doubles.asList(0.01, 0.1, 0.25, 0.499, 0.5, 0.501, 0.7, 0.8)) {
        double x = d + delta;
        if (x != Math.round(x)) {
          fractionalBuilder.add(x);
        }
      }

      // This range is [-5, 4] - slight negative bias so we often hit zero, which brings the
      // auto-removal of zeroes into play.
      int delta = random.nextInt(10) - 5;
      blah += delta;
      if (delta >= 0) {
        multiset.add(key, delta);
      } else {
        multiset.remove(key, -delta);
      }
    }
    return blah;
  }

  private enum MultisetSupplier {
    CONCURRENT_HASH_MULTISET() {

      InternetDomainName.from("xn--jrpeland-54a.no");

  /** The Greek letter delta, used in unicode testing. */
  private static final String DELTA = "\u0394";

  /** A domain part which is valid under lenient validation, but invalid under strict validation. */
  static final String LOTS_OF_DELTAS = Strings.repeat(DELTA, 62);

  private static final String ALMOST_TOO_MANY_LEVELS = Strings.repeat("a.", 127);

      // http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax

      int delta = a - b; // can't overflow, since a and b are nonnegative

      int minDeltaOrZero = delta & (delta >> (Integer.SIZE - 1));
      // equivalent to Math.min(delta, 0)

      a = delta - minDeltaOrZero - minDeltaOrZero; // sets a to Math.abs(a - b)
      // a is now nonnegative and even

      InternetDomainName.from("xn--jrpeland-54a.no");

  /** The Greek letter delta, used in unicode testing. */
  private static final String DELTA = "\u0394";

  /** A domain part which is valid under lenient validation, but invalid under strict validation. */
  static final String LOTS_OF_DELTAS = Strings.repeat(DELTA, 62);

  private static final String ALMOST_TOO_MANY_LEVELS = Strings.repeat("a.", 127);

   * size() as a hint only.
   *
   * @param delta the difference between the true size of the collection and the values returned by
   *     the size method
   */
  public static <T extends @Nullable Object> Collection<T> misleadingSizeCollection(int delta) {
    // It would be nice to be able to return a real concurrent

import com.google.common.collect.testing.SampleElements.Unhashables;
import java.util.Collection;
import java.util.List;

/**
 * Creates collections containing unhashable sample elements, to be tested.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class TestUnhashableCollectionGenerator<T extends Collection<UnhashableObject>>
    implements TestCollectionGenerator<UnhashableObject> {
  @Override

 * relying on any specific Set implementations. Slow. Explicitly allows null elements so that they
 * can be used in the testers.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class MinimalSet<E extends @Nullable Object> extends MinimalCollection<E> implements Set<E> {

  @SuppressWarnings("unchecked") // empty Object[] as E[]

 * relying on any specific Set implementations. Slow. Explicitly allows null elements so that they
 * can be used in the testers.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class MinimalSet<E extends @Nullable Object> extends MinimalCollection<E> implements Set<E> {

  @SuppressWarnings("unchecked") // empty Object[] as E[]

  }

  public void testToArray_threadSafe() {
    for (int delta : new int[] {+1, 0, -1}) {
      for (int i = 0; i < VALUES.length; i++) {
        List<Byte> list = Bytes.asList(VALUES).subList(0, i);
        Collection<Byte> misleadingSize = Helpers.misleadingSizeCollection(delta);
        misleadingSize.addAll(list);
        byte[] arr = Bytes.toArray(misleadingSize);