assertEquals(
        "next() should still return first element after peeking", "A", peekingIterator.next());

    assertEquals("Should be able to peek() at middle element", "B", peekingIterator.peek());
    assertEquals(
        "Should be able to peek() middle element multiple times", "B", peekingIterator.peek());
    assertEquals(

    assertTrue(cycle.hasNext());
    assertEquals("a", cycle.next());
    cycle.remove();
    assertEquals(singletonList("b"), iterable);
    assertTrue(cycle.hasNext());
    assertEquals("b", cycle.next());
    assertTrue(cycle.hasNext());
    assertEquals("b", cycle.next());
    cycle.remove();
    assertEquals(emptyList(), iterable);
    assertFalse(cycle.hasNext());
  }

    assertThrows(NoSuchElementException.class, () -> iterator.next());
    assertThrows(IllegalStateException.class, () -> iterable.iterator());
  }

  public void testOf_one() {
    Iterable<String> iterable = MinimalIterable.of("a");
    Iterator<String> iterator = iterable.iterator();
    assertTrue(iterator.hasNext());
    assertEquals("a", iterator.next());
    assertFalse(iterator.hasNext());

      @Override
      @ParametricNullness
      public T next() {
        T next = iterator.next();
        iterator.remove();
        return next;
      }

      @Override
      public String toString() {
        return "Iterators.consumingIterator(...)";
      }
    };
  }

  /**
   * Deletes and returns the next value from the iterator, or returns {@code null} if there is no

    assertTrue(cycle.hasNext());
    assertEquals("a", cycle.next());
    cycle.remove();
    assertEquals(singletonList("b"), iterable);
    assertTrue(cycle.hasNext());
    assertEquals("b", cycle.next());
    assertTrue(cycle.hasNext());
    assertEquals("b", cycle.next());
    cycle.remove();
    assertEquals(emptyList(), iterable);
    assertFalse(cycle.hasNext());
  }

    assertEquals((Integer) 12, it.next());
    assertEquals((Integer) 30, it.next());
    assertEquals((Integer) 40, it.next());
    // Skipping 20
    assertEquals((Integer) 11, it.next());
    // Not skipping 400, because it moved back down
    assertEquals((Integer) 400, it.next());
    assertEquals((Integer) 13, it.next());
    assertEquals((Integer) 200, it.next());
    assertEquals((Integer) 300, it.next());

    assertEquals(
        "next() should still return first element after peeking", "A", peekingIterator.next());

    assertEquals("Should be able to peek() at middle element", "B", peekingIterator.peek());
    assertEquals(
        "Should be able to peek() middle element multiple times", "B", peekingIterator.peek());
    assertEquals(

    assertEquals((Integer) 12, it.next());
    assertEquals((Integer) 30, it.next());
    assertEquals((Integer) 40, it.next());
    // Skipping 20
    assertEquals((Integer) 11, it.next());
    // Not skipping 400, because it moved back down
    assertEquals((Integer) 400, it.next());
    assertEquals((Integer) 13, it.next());
    assertEquals((Integer) 200, it.next());
    assertEquals((Integer) 300, it.next());

     * stack so that it is returned by the next call to {@link Iterator#next()}. If the element is
     * not in {@link #nextElements}, this method throws an {@link UnknownElementException}.
     *
     * <p>This method is used when testing iterators without a known ordering. We poll the target
     * iterator's next element and pass it to the reference iterator through this method so it can

    assertEquals(
        "multiset.entrySet() iterator.next() returned incorrect entry",
        Multisets.immutableEntry(e0(), 1),
        iterator.next());
    assertFalse(
        "size 1 multiset.entrySet() iterator.hasNext() returned true after next()",
        iterator.hasNext());
    iterator.remove();
    assertTrue(