protected List<String> create(String[] elements) {
      return ImmutableList.copyOf(elements);
    }
  }

  public static class BuilderAddListGenerator extends TestStringListGenerator {
    @Override
    protected List<String> create(String[] elements) {
      ImmutableList.Builder<String> builder = ImmutableList.builder();
      for (String element : elements) {
        builder.add(element);
      }
      return builder.build();

  @Override
  void setCountCheckReturnValue(E element, int count) {
    assertEquals(
        "multiset.setCount() should return the old count",
        getMultiset().count(element),
        setCount(element, count));
  }

  @Override
  void setCountNoCheckReturnValue(E element, int count) {
    setCount(element, count);
  }

  @CanIgnoreReturnValue
  private int setCount(E element, int count) {

import java.util.NoSuchElementException;
import org.jspecify.annotations.Nullable;

/**
 * This class provides a skeletal implementation of the {@code Iterator} interface for sequences
 * whose next element can always be derived from the previous element. Null elements are not
 * supported, nor is the {@link #remove()} method.
 *
 * <p>Example:
 *
 * {@snippet :
 * Iterator<Integer> powersOfTwo =
 *     new AbstractSequentialIterator<Integer>(1) {

  final transient E element;

  SingletonImmutableSet(E element) {
    this.element = Preconditions.checkNotNull(element);
  }

  @Override
  public int size() {
    return 1;
  }

  @Override
  public boolean contains(@Nullable Object target) {
    return element.equals(target);
  }

  @Override
  public UnmodifiableIterator<E> iterator() {

                Map<Object, Object> context = Collections.emptyMap();

                for (Plugin element : src) {
                    Object key = getPluginKey(element);
                    managedPlugins.put(key, element);
                }

                for (Plugin element : tgt) {
                    Object key = getPluginKey(element);
                    Plugin managedPlugin = managedPlugins.get(key);

  }

  protected void expectMissingKeys(K... elements) {
    for (K element : elements) {
      assertFalse("Should not contain key " + element, getMap().containsKey(element));
    }
  }

  protected void expectMissingValues(V... elements) {
    for (V element : elements) {
      assertFalse("Should not contain value " + element, getMap().containsValue(element));
    }
  }

  /**

	// Next and previous pointers in the doubly-linked list of elements.
	// To simplify the implementation, internally a list l is implemented
	// as a ring, such that &l.root is both the next element of the last
	// list element (l.Back()) and the previous element of the first list
	// element (l.Front()).
	next, prev *Entry[K, V]

	// The list to which this element belongs.
	list *LruList[K, V]

   * nulls as long as the *last* element is *not* null.
   *
   * (To "go out of its way," the method tracks a `set` bit so that it can distinguish "the final
   * split has a last element of null, so throw NPE" from "the final split was empty, so look for an
   * element in the prior one.")
   */
  public static <T> java.util.Optional<T> findLast(Stream<T> stream) {
    final class OptionalState {
      boolean set = false;

  @Override
  public int add(@ParametricNullness E element, int occurrences) {
    if (occurrences == 0) {
      return count(element);
    }
    checkArgument(occurrences > 0, "occurrences cannot be negative: %s", occurrences);
    Count frequency = backingMap.get(element);
    int oldCount;
    if (frequency == null) {
      oldCount = 0;
      backingMap.put(element, new Count(occurrences));
    } else {

   * UnsupportedOperationException."
   */
  abstract void setCountNoCheckReturnValue(E element, int count);

  private void assertSetCountIncreasingFailure(E element, int count) {
    try {
      setCountNoCheckReturnValue(element, count);
      fail("a call to multiset.setCount() to increase an element's count should throw");
    } catch (UnsupportedOperationException expected) {
    }
  }