import com.google.common.collect.testing.features.CollectionFeature;
import java.lang.reflect.Method;
import java.util.Iterator;
import java.util.List;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * Tester to make sure the {@code iterator().remove()} implementation of {@code Multiset} works when
 * there are multiple occurrences of elements.
 *

  /**
   * A sensible definition of {@link #firstEntry()} in terms of {@code entrySet().iterator()}.
   *
   * <p>If you override {@link #entrySet()}, you may wish to override {@link #firstEntry()} to
   * forward to this implementation.
   */
  protected @Nullable Entry<E> standardFirstEntry() {
    Iterator<Entry<E>> entryIterator = entrySet().iterator();
    if (!entryIterator.hasNext()) {
      return null;
    }

  public void testPutAbsentConcurrentWithEntrySetIteration() {
    assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<Entry<K, V>> iterator = getMap().entrySet().iterator();
          put(e3());
          iterator.next();
        });
  }

  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_PUT})
  @CollectionSize.Require(absent = ZERO)

  public void testRemoveAllSomePresentConcurrentWithIteration() {
    assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<E> iterator = collection.iterator();
          assertTrue(collection.removeAll(MinimalCollection.of(e0(), e3())));
          iterator.next();
        });
  }

  /** Trigger the {@code other.size() >= this.size()} case in {@link AbstractSet#removeAll}. */

    Iterator<Entry<K, V>> iterator = multimap().entries().iterator();
    assertEquals(mapEntry(k0(), v0()), iterator.next());
    iterator.remove();
    assertTrue(multimap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testEntriesRemainValidAfterRemove() {
    Iterator<Entry<K, V>> iterator = multimap().entries().iterator();

  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testIteratorRemove_unsupported() {
    Iterator<E> iterator = collection.iterator();
    iterator.next();
    assertThrows(UnsupportedOperationException.class, iterator::remove);
    expectUnchanged();
    assertTrue(collection.contains(e0()));
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)

    assertEquals("", j.join(ImmutableMultimap.of().entries().iterator()));
    assertEquals(":", j.join(ImmutableMultimap.of("", "").entries()));
    assertEquals(":", j.join(ImmutableMultimap.of("", "").entries().iterator()));
    assertEquals("1:a;1:b", j.join(ImmutableMultimap.of("1", "a", "1", "b").entries()));
    assertEquals("1:a;1:b", j.join(ImmutableMultimap.of("1", "a", "1", "b").entries().iterator()));

        final List methods = (List) getHeaderFields0().get(authHeader);
        if (methods == null) {
            return null;
        }
        final Iterator iterator = methods.iterator();
        while (iterator.hasNext()) {
            final String currentAuthMethod = (String) iterator.next();
            if (currentAuthMethod.startsWith("NTLM")) {
                if (currentAuthMethod.length() == 4) {
                    authMethod = "NTLM";

  }

  static <T extends @Nullable Object> Iterator<T> cycle(Iterable<T> iterable) {
    return new Iterator<T>() {
      Iterator<T> iterator = Collections.<T>emptySet().iterator();

      @Override
      public boolean hasNext() {
        return true;
      }

      @Override
      public T next() {
        if (!iterator.hasNext()) {
          iterator = iterable.iterator();
        }

    assertFalse(getMap().entrySet().iterator().hasNext());
  }

  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
  @CollectionSize.Require(SEVERAL)
  public void testClearConcurrentWithEntrySetIteration() {
    assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<Entry<K, V>> iterator = getMap().entrySet().iterator();
          getMap().clear();