}
    }.test();
  }

  @CollectionFeature.Require(value = SUPPORTS_ITERATOR_REMOVE, absent = KNOWN_ORDER)
  public void testRemovingIteratorUnknownOrder() {
    new IteratorTester<E>(
        4,
        MODIFIABLE,
        Arrays.asList(e0(), e1(), e1(), e2()),
        IteratorTester.KnownOrder.UNKNOWN_ORDER) {
      @Override
      protected Iterator<E> newTargetIterator() {

    CharEscaper replacingEscaper =
        new ArrayBasedCharEscaper(SIMPLE_REPLACEMENTS, ' ', '~') {
          private final char[] unknown = new char[] {'?'};

          @Override
          protected char[] escapeUnsafe(char c) {
            return unknown;
          }
        };
    EscaperAsserts.assertBasic(replacingEscaper);

    // Replacements are applied first regardless of whether the character is in

        assertThat(graph.removeNode(nodeList.get(i))).isTrue();
      }

      assertThat(graph.nodes()).hasSize(NUM_NODES - numNodesToRemove);
      // Number of edges remaining is unknown (node's incident edges have been removed).
      AbstractGraphTest.validateGraph(graph);

      for (int i = numNodesToRemove; i < NUM_NODES; ++i) {
        assertThat(graph.removeNode(nodeList.get(i))).isTrue();
      }

      Helpers.addAll(elements, previousElements);
      Helpers.addAll(elements, Helpers.reverse(nextElements));
      return elements;
    }
  }

  public enum KnownOrder {
    KNOWN_ORDER,
    UNKNOWN_ORDER
  }

  @SuppressWarnings("unchecked") // TODO(cpovirk): Stop using arrays.
  AbstractIteratorTester(
      int steps,
      Iterable<E> elementsToInsertIterable,

    CharEscaper replacingEscaper =
        new ArrayBasedCharEscaper(SIMPLE_REPLACEMENTS, ' ', '~') {
          private final char[] unknown = new char[] {'?'};

          @Override
          protected char[] escapeUnsafe(char c) {
            return unknown;
          }
        };
    EscaperAsserts.assertBasic(replacingEscaper);

    // Replacements are applied first regardless of whether the character is in

          @Override
          protected Iterator<Integer> newTargetIterator() {
            return ImmutableList.of(1, 2).iterator();
          }
        };
    assertFailure(tester);
  }

  public void testUnknownOrder() {
    new IteratorTester<Integer>(
        3, MODIFIABLE, newArrayList(1, 2), IteratorTester.KnownOrder.UNKNOWN_ORDER) {
      @Override

        // Find the ValueParser for the current key.
        String key = keyAndValue.get(0);
        ValueParser valueParser = VALUE_PARSERS.get(key);
        checkArgument(valueParser != null, "unknown key %s", key);

        String value = keyAndValue.size() == 1 ? null : keyAndValue.get(1);
        valueParser.parse(spec, key, value);
      }
    }

    return spec;
  }

        assertThat(network.removeNode(nodeList.get(i))).isTrue();
      }

      assertThat(network.nodes()).hasSize(NUM_NODES - numNodesToRemove);
      // Number of edges remaining is unknown (node's incident edges have been removed).
      AbstractNetworkTest.validateNetwork(network);

      for (int i = numNodesToRemove; i < NUM_NODES; ++i) {
        assertThat(network.removeNode(nodeList.get(i))).isTrue();

 * it</a>.
 */
@GwtCompatible
@Retention(RUNTIME)
@Target({FIELD, METHOD, PARAMETER})
@javax.annotation.meta.TypeQualifierNickname
@javax.annotation.Nonnull(when = javax.annotation.meta.When.UNKNOWN)

 * it</a>.
 */
@GwtCompatible
@Retention(RUNTIME)
@Target({FIELD, METHOD, PARAMETER})
@javax.annotation.meta.TypeQualifierNickname
@javax.annotation.Nonnull(when = javax.annotation.meta.When.UNKNOWN)