abstract class EndpointPairIterator<N> extends AbstractIterator<EndpointPair<N>> {
  private final BaseGraph<N> graph;
  private final Iterator<N> nodeIterator;

  @CheckForNull
  N node = null; // null is safe as an initial value because graphs don't allow null nodes

  Iterator<N> successorIterator = ImmutableSet.<N>of().iterator();

  static <N> EndpointPairIterator<N> of(BaseGraph<N> graph) {

      }
    }
  }

  /**
   * Returns an iterator over the elements contained in this collection, <i>in no particular
   * order</i>.
   *
   * <p>The iterator is <i>fail-fast</i>: If the MinMaxPriorityQueue is modified at any time after
   * the iterator is created, in any way except through the iterator's own remove method, the
   * iterator will generally throw a {@link ConcurrentModificationException}. Thus, in the face of

    } catch (IllegalArgumentException e) {
      return emptySet(comparator());
    }
  }

  @CheckForNull
  E higher(E e) {
    checkNotNull(e);
    Iterator<E> iterator = tailSet(e).iterator();
    while (iterator.hasNext()) {
      E higher = iterator.next();
      if (comparator().compare(e, higher) < 0) {
        return higher;
      }
    }
    return null;
  }

  @CheckForNull

    Iterator<Integer> iterator = ints.iterator();
    assertEquals(0, (int) numberOrdering.min(iterator));
    assertFalse(iterator.hasNext());
  }

  public void testIteratorMaxExhaustsIterator() {
    List<Integer> ints = Lists.newArrayList(9, 0, 3, 5);
    Iterator<Integer> iterator = ints.iterator();
    assertEquals(9, (int) numberOrdering.max(iterator));
    assertFalse(iterator.hasNext());

    Iterator<Integer> iterator = ints.iterator();
    assertEquals(0, (int) numberOrdering.min(iterator));
    assertFalse(iterator.hasNext());
  }

  public void testIteratorMaxExhaustsIterator() {
    List<Integer> ints = Lists.newArrayList(9, 0, 3, 5);
    Iterator<Integer> iterator = ints.iterator();
    assertEquals(9, (int) numberOrdering.max(iterator));
    assertFalse(iterator.hasNext());

                }
            });
        }
    }

    @Override
    public Iterator<Lifecycle> iterator() {
        return stream().toList().iterator();
    }

    @Override
    public Stream<Lifecycle> stream() {
        return providers.stream().map(ExtensibleEnumProvider::provides).flatMap(Collection::stream);
    }

    assertThat(multimap.keySet()).containsExactly("foo", "bar", "cow").inOrder();
    assertThat(multimap.values()).containsExactly(5, 4, 3, 2, 1).inOrder();

    Iterator<Entry<String, Integer>> entryIterator = multimap.entries().iterator();
    assertEquals(immutableEntry("foo", 5), entryIterator.next());
    assertEquals(immutableEntry("bar", 4), entryIterator.next());

    int dummy = 0;
    for (int i = 0; i < reps; i++) {
      StringBuilder sb = new StringBuilder();
      Iterator<String> iterator = components.iterator();
      if (iterator.hasNext()) {
        sb.append(iterator.next().toString());
        while (iterator.hasNext()) {
          sb.append(DELIMITER_STRING);
          sb.append(iterator.next());
        }
      }
      dummy ^= sb.toString().length();
    }
    return dummy;
  }

    Iterator<Integer> iter =
        new AbstractIterator<Integer>() {
          @Override
          public Integer computeNext() {
            endOfData();
            throw new SomeUncheckedException();
          }
        };
    assertThrows(SomeUncheckedException.class, iter::hasNext);
  }

  public void testCantRemove() {
    Iterator<Integer> iter =

        assertThat(lru.get("aaa"), is("111"));
        Iterator<String> i = lru.keySet().iterator();
        assertThat(i.next(), is("bbb"));
        assertThat(i.next(), is("ccc"));
        assertThat(i.next(), is("aaa"));
        lru.put("ddd", "444");
        assertThat(lru.size(), is(3));
        assertThat(lru.get("bbb"), is(nullValue()));
        i = lru.keySet().iterator();
        assertThat(i.next(), is("ccc"));