var unionWith: Mapping = mapping
    index++

    while (index < mappings.size) {
      val next = mappings[index]

      if (type != canonicalizeType(next.type)) break
      if (type == TYPE_MAPPED && mappedTo != next.mappedTo) break

      unionWith = next
      index++
    }

    result +=
      Mapping(
        sourceCodePoint0 = mapping.sourceCodePoint0,

        if (element == null) {
            for (Entry e = header.next; e != header; e = e.next) {
                if (e.element == null) {
                    e.remove();
                    return true;
                }
            }
        } else {
            for (Entry e = header.next; e != header; e = e.next) {
                if (element.equals(e.element)) {
                    e.remove();

    // Safe because hasNext() ensures that tryToComputeNext() has put a T into `next`.
    T result = uncheckedCastNullableTToT(next);
    next = null;
    return result;
  }

  /**
   * Returns the next element in the iteration without advancing the iteration, according to the
   * contract of {@link PeekingIterator#peek()}.
   *

    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());
  }

        final LineIterator it = new LineIterator(reader);
        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is("aaa"));
        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is("bbb"));
        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is("ccc"));
        assertThat(it.hasNext(), is(not(true)));
    }

    /**
     * @throws Exception
     */
    @Test

        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is(sameInstance(cl3)));

        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is(sameInstance(cl2)));

        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is(sameInstance(cl1)));

        assertThat(it.hasNext(), is(not(true)));
    }

    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());

        throw new IllegalStateException();
      }
      iterator.remove();
    }
  }

  public void testCanCatchSunJavaBug6529795InTargetIterator() {
    try {
      /* Choose 4 steps to get sequence [next, next, next, remove] */
      new IteratorTester<Integer>(
          4, MODIFIABLE, newArrayList(1, 2), IteratorTester.KnownOrder.KNOWN_ORDER) {
        @Override
        protected Iterator<Integer> newTargetIterator() {

    assertTrue(iterator.hasNext());
    assertEquals("a", iterator.next());
    assertThrows(UnsupportedOperationException.class, () -> iterator.remove());
  }

  @SuppressWarnings("DoNotCall")
  public void testAdd() {
    ListIterator<String> iterator = create();

    assertTrue(iterator.hasNext());
    assertEquals("a", iterator.next());
    assertEquals("b", iterator.next());
    assertEquals("b", iterator.previous());