public void testCopyOf_iterator_oneElementRepeated() {
    Iterator<String> iterator = Iterators.forArray("a", "a", "a");
    Set<String> set = copyOf(iterator);
    assertEquals(singleton("a"), set);
  }

  public void testCopyOf_iterator_general() {
    Iterator<String> iterator = Iterators.forArray("a", "b", "a");
    Set<String> set = copyOf(iterator);
    assertEquals(2, set.size());
    assertTrue(set.contains("a"));

      }

      @Override
      Iterator<E> elementIterator() {
        throw new AssertionError("should never be called");
      }

      @Override
      Iterator<Entry<E>> entryIterator() {
        Iterator<? extends Entry<? extends E>> iterator1 = multiset1.entrySet().iterator();
        Iterator<? extends Entry<? extends E>> iterator2 = multiset2.entrySet().iterator();

      }

      @Override
      Iterator<E> elementIterator() {
        throw new AssertionError("should never be called");
      }

      @Override
      Iterator<Entry<E>> entryIterator() {
        Iterator<? extends Entry<? extends E>> iterator1 = multiset1.entrySet().iterator();
        Iterator<? extends Entry<? extends E>> iterator2 = multiset2.entrySet().iterator();

      @Override
      public UnmodifiableIterator<E> iterator() {
        Iterable<E> incidentEdges =
            (selfLoopCount == 0)
                ? Iterables.concat(inEdgeMap.keySet(), outEdgeMap.keySet())
                : Sets.union(inEdgeMap.keySet(), outEdgeMap.keySet());
        return Iterators.unmodifiableIterator(incidentEdges.iterator());
      }

      @Override
      public int size() {

    this.targetNode = checkNotNull(targetNode);
  }

  @Override
  public UnmodifiableIterator<E> iterator() {
    E connectingEdge = getConnectingEdge();
    return (connectingEdge == null)
        ? ImmutableSet.<E>of().iterator()
        : Iterators.singletonIterator(connectingEdge);
  }

  @Override
  public int size() {
    return getConnectingEdge() == null ? 0 : 1;
  }

import java.util.Collections;
import java.util.Iterator;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A utility for testing an Iterator implementation by comparing its behavior to that of a "known
 * good" reference implementation. In order to accomplish this, it's important to test a great
 * variety of sequences of the {@link Iterator#next}, {@link Iterator#hasNext} and {@link

  private abstract class Itr<T extends @Nullable Object> implements Iterator<T> {
    final Iterator<Entry<K, Collection<V>>> keyIterator;
    @Nullable K key;
    @Nullable Collection<V> collection;
    Iterator<V> valueIterator;

    Itr() {
      keyIterator = map.entrySet().iterator();
      key = null;
      collection = null;
      valueIterator = Iterators.emptyModifiableIterator();
    }

          return standardToArray(array);
        }
      };
    }

    private static <K, V extends @Nullable Object> Iterator<Entry<K, V>> transformEntries(
        Iterator<Entry<K, V>> entries) {
      return Iterators.transform(entries, UnmodifiableEntry::new);
    }

    private UnmodifiableEntry(Entry<K, V> delegate) {
      this.delegate = checkNotNull(delegate);
    }

      @Override
      public UnmodifiableIterator<E> iterator() {
        Iterable<E> incidentEdges =
            (selfLoopCount == 0)
                ? Iterables.concat(inEdgeMap.keySet(), outEdgeMap.keySet())
                : Sets.union(inEdgeMap.keySet(), outEdgeMap.keySet());
        return Iterators.unmodifiableIterator(incidentEdges.iterator());
      }

      @Override
      public int size() {

    return adjacentNodes();
  }

  @Override
  public Set<N> successors() {
    return adjacentNodes();
  }

  @Override
  public Iterator<EndpointPair<N>> incidentEdgeIterator(N thisNode) {
    return Iterators.transform(
        adjacentNodeValues.keySet().iterator(),
        (N incidentNode) -> EndpointPair.unordered(thisNode, incidentNode));
  }

  @Override
  public @Nullable V value(N node) {