}

  public void testSize1() {
    Iterator<Integer> iterator = singleton(0).iterator();
    assertEquals(1, Iterators.size(iterator));
  }

  public void testSize_partiallyConsumed() {
    Iterator<Integer> iterator = asList(1, 2, 3, 4, 5).iterator();
    iterator.next();
    iterator.next();
    assertEquals(3, Iterators.size(iterator));
  }

   *
   * <p>Note: The input {@code Iterator} will be copied to an {@code ImmutableList} when this method
   * is called. This will fail if the iterator is infinite and may cause problems if the iterator
   * eagerly fetches data for each source when iterated (rather than producing sources that only
   * load data through their streams). Prefer using the {@link #concat(Iterable)} overload if
   * possible.
   *

      TestSubjectGenerator<? extends Iterable<E>> collectionGenerator) {
    this.collectionGenerator = collectionGenerator;
  }

  @Override
  public TestSubjectGenerator<? extends Iterable<E>> getInnerGenerator() {
    return collectionGenerator;
  }

  @Override
  public Iterator<E> get() {
    return collectionGenerator.createTestSubject().iterator();
  }

    return singletonMap(key, value).entrySet().iterator().next();
  }

  private static boolean isEmpty(Iterable<?> iterable) {
    return iterable instanceof Collection
        ? ((Collection<?>) iterable).isEmpty()
        : !iterable.iterator().hasNext();
  }

  public static void assertEmpty(Iterable<?> iterable) {
    if (!isEmpty(iterable)) {
      fail("Not true that " + iterable + " is empty");
    }
  }

      default:
        return create(elements);
    }
  }

  public static <E> ImmutableSet<E> copyOf(Collection<? extends E> elements) {
    Iterable<? extends E> iterable = elements;
    return copyOf(iterable);
  }

  public static <E> ImmutableSet<E> copyOf(Iterable<? extends E> elements) {
    if (elements instanceof ImmutableSet && !(elements instanceof ImmutableSortedSet)) {

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

    this.elementOrder = elementOrder;
  }

  @Override
  public int compare(Iterable<T> leftIterable, Iterable<T> rightIterable) {
    Iterator<T> left = leftIterable.iterator();
    Iterator<T> right = rightIterable.iterator();
    while (left.hasNext()) {
      if (!right.hasNext()) {
        return LEFT_IS_GREATER; // because it's longer
      }

    this.elementOrder = elementOrder;
  }

  @Override
  public int compare(Iterable<T> leftIterable, Iterable<T> rightIterable) {
    Iterator<T> left = leftIterable.iterator();
    Iterator<T> right = rightIterable.iterator();
    while (left.hasNext()) {
      if (!right.hasNext()) {
        return LEFT_IS_GREATER; // because it's longer
      }

        lastFromForgetMeNot = null;
      }
    }

    /** Returns true if an exact reference (==) was found and removed from the supplied iterable. */
    private boolean foundAndRemovedExactReference(Iterable<E> elements, E target) {
      for (Iterator<E> it = elements.iterator(); it.hasNext(); ) {
        E element = it.next();
        if (element == target) {
          it.remove();
          return true;
        }

      @Override
      public Iterator<String> iterator() {
        return splittingIterator(sequence);
      }

      @Override
      public String toString() {
        return Joiner.on(", ")
            .appendTo(new StringBuilder().append('['), this)
            .append(']')
            .toString();
      }
    };
  }