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());

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

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

    assertTrue(iterator.hasNext());
    assertThat(iterator.next()).isEqualTo("a");
    assertThat(iterator.next()).isEqualTo("b");

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

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

    assertTrue(iterator.hasNext());
    assertThat(iterator.next()).isEqualTo("a");
    assertThat(iterator.next()).isEqualTo("b");

   */
  public abstract @Nullable C previous(C value);

  /**
   * Returns a signed value indicating how many nested invocations of {@link #next} (if positive) or
   * {@link #previous} (if negative) are needed to reach {@code end} starting from {@code start}.
   * For example, if {@code end = next(next(next(start)))}, then {@code distance(start, end) == 3}
   * and {@code distance(end, start) == -3}. As well, {@code distance(a, a)} is always zero.
   *

        /** The element */
        protected E element;

        /** The next entry */
        protected Entry next;

        /** The previous entry */
        protected Entry previous;

        Entry(final E element, final Entry next, final Entry previous) {
            this.element = element;
            this.next = next;
            this.previous = previous;
        }

        /**

                assertFalse(iterator3.hasNext(), "Third instance should have no elements");

                assertNull(iterator1.next(), "First instance next() should return null");
                assertNull(iterator2.next(), "Second instance next() should return null");
                assertNull(iterator3.next(), "Third instance next() should return null");
            } catch (CIFSException e) {
                throw new RuntimeException(e);
            }

    assertRoute(selection.next(), address, Proxy.NO_PROXY, dns.lookup(uriHost, 0), uriPort)
    assertThat(selection.hasNext()).isFalse()
    assertFailsWith<NoSuchElementException> {
      selection.next()
    }
    assertThat(routeSelector.hasNext()).isFalse()
    assertFailsWith<NoSuchElementException> {
      routeSelector.next()
    }
  }

  @Test fun explicitProxyTriesThatProxysAddressesOnly() {
    val address =

        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is(sameClass(Integer.class)));

        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is(sameClass(Number.class)));

        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is(sameClass(Object.class)));

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

    /**

      private final StrongKeyStrongValueEntry<K, V> next;

      LinkedStrongKeyStrongValueEntry(K key, int hash, StrongKeyStrongValueEntry<K, V> next) {
        super(key, hash);
        this.next = next;
      }

      @Override
      public StrongKeyStrongValueEntry<K, V> getNext() {
        return next;
      }
    }

      return;
    }
    if (map.size() < 2 || !supportsPut) {
      return;
    }
    Iterator<Entry<K, V>> iterator = map.entrySet().iterator();
    Entry<K, V> firstEntry = iterator.next();
    Entry<K, V> secondEntry = iterator.next();
    K key = secondEntry.getKey();
    SortedMap<K, V> subMap = map.tailMap(key);
    V value = getValueNotInPopulatedMap();
    subMap.put(key, value);