* If {@code element} is not {@code null}, child configuration element with the specified name will
     * be unmarshalled.
     *
     * @param configuration The configuration to unmarshal, may be {@code null}.
     * @param element Configuration element name to unmarshal or {@code null} to unmarshal entire configuration.

        for (int i = 0; i < elements.length; i++) {
          String element = elements[i];
          if (multiset1.contains(element) || multiset2.contains(element)) {
            // add to both; the one already containing it will have more
            multiset1.add(element);
            multiset2.add(element);
          } else if (i % 2 == 0) {
            multiset1.add(elements[i]);
          } else {

 *
 * List<String> list = ...;
 * Set<String> set = ...;
 * Map<String, Object> map = ...;
 * for (String element : iterable(list, set, map.keySet())) {
 *     ...
 * }
 * </pre>
 *
 * @author koichik
 * @param <E> the element type
 */
public class MultiIterator<E> implements Iterator<E> {

    /** Array of {@link Iterator}s. */
    protected final Iterator<E>[] iterators;

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 =

 */
package org.apache.maven.plugin.descriptor;

/**
 */
public class InvalidParameterException extends InvalidPluginDescriptorException {
    public InvalidParameterException(String element, int i) {
        super("The " + element + " element in parameter # " + i + " is invalid. It cannot be null.");
    }

    public InvalidParameterException(String message, Throwable cause) {
        super(message, cause);
    }

  }

  /**
   * Adds the given element to this queue. If the queue is currently full, the element at the head
   * of the queue is evicted to make room.
   *
   * @return {@code true} always
   */
  @Override
  @CanIgnoreReturnValue
  public boolean offer(E e) {
    return add(e);
  }

  /**
   * Adds the given element to this queue. If the queue is currently full, the element at the head

  }

  /**
   * Adds the given element to this queue. If the queue is currently full, the element at the head
   * of the queue is evicted to make room.
   *
   * @return {@code true} always
   */
  @Override
  @CanIgnoreReturnValue
  public boolean offer(E e) {
    return add(e);
  }

  /**
   * Adds the given element to this queue. If the queue is currently full, the element at the head

  /** Constructor for use by subclasses. */
  protected ForwardingListIterator() {}

  @Override
  protected abstract ListIterator<E> delegate();

  @Override
  public void add(@ParametricNullness E element) {
    delegate().add(element);
  }

  @Override
  public boolean hasPrevious() {
    return delegate().hasPrevious();
  }

  @Override
  public int nextIndex() {
    return delegate().nextIndex();
  }

        for (int i = 0; i < elements.length; i++) {
          String element = elements[i];
          if (multiset1.contains(element) || multiset2.contains(element)) {
            // add to both; the one already containing it will have more
            multiset1.add(element);
            multiset2.add(element);
          } else if (i % 2 == 0) {
            multiset1.add(elements[i]);
          } else {

    assertTrue(
        "multiset.entrySet.remove(presentEntry) returned false",
        getMultiset().entrySet().remove(Multisets.immutableEntry(e0(), 1)));
    assertFalse("multiset contains element after removing its entry", getMultiset().contains(e0()));
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testEntrySet_removeAbsent() {
    assertFalse(