* called more than once to add features in multiple groups.
   */
  @CanIgnoreReturnValue
  public B withFeatures(Feature<?>... features) {
    return withFeatures(asList(features));
  }

  @CanIgnoreReturnValue
  public B withFeatures(Iterable<? extends Feature<?>> features) {
    for (Feature<?> feature : features) {
      this.features.add(feature);
    }
    return self();

    TestSuite suite = new TestSuite();

    suite.addTest(
        NavigableSetTestSuiteBuilder.using(new ImmutableSortedSetCopyOfGenerator())
            .named(ImmutableSortedSetTest.class.getName())
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.KNOWN_ORDER,
                CollectionFeature.SERIALIZABLE,
                CollectionFeature.ALLOWS_NULL_QUERIES)
            .createTestSuite());

  }

  @Override
  public TestSuite createTestSuite() {
    if (!getFeatures().contains(KNOWN_ORDER)) {
      List<Feature<?>> features = copyToList(getFeatures());
      features.add(KNOWN_ORDER);
      withFeatures(features);
    }
    return super.createTestSuite();
  }

  @Override
  protected List<TestSuite> createDerivedSuites(
      FeatureSpecificTestSuiteBuilder<

                    return new StandardImplForwardingList<>(Lists.newArrayList(elements));
                  }
                })
            .named("ForwardingList[ArrayList] with standard implementations")
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.ALLOWS_NULL_VALUES,
                ListFeature.GENERAL_PURPOSE)
            .createTestSuite());
    suite.addTest(

                      map.put(entry.getKey(), entry.getValue());
                    }
                    return map;
                  }
                })
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.KNOWN_ORDER,
                CollectionFeature.SERIALIZABLE,
                MapFeature.ALLOWS_NULL_VALUES,

                      map.put(entry.getKey(), entry.getValue());
                    }
                    return map;
                  }
                })
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.KNOWN_ORDER,
                CollectionFeature.SERIALIZABLE,
                MapFeature.ALLOWS_NULL_VALUES,

                  public List<String> order(List<String> insertionOrder) {
                    return new ArrayList<>(Sets.newTreeSet(insertionOrder));
                  }
                })
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.KNOWN_ORDER,
                CollectionFeature.GENERAL_PURPOSE)
            .named("SafeTreeSet with natural comparator")

                        LinkedHashMultiset.create(asList(elements)));
                  }
                })
            .named("ForwardingMultiset[LinkedHashMultiset] with standard implementations")
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.ALLOWS_NULL_VALUES,
                CollectionFeature.GENERAL_PURPOSE)
            .createTestSuite());
    suite.addTest(

                unfiltered.add("zzz");
                return Collections2.filter(unfiltered, NOT_YYY_ZZZ);
              }
            })
        .named("Collections2.filter")
        .withFeatures(
            CollectionFeature.SUPPORTS_ADD,
            CollectionFeature.SUPPORTS_REMOVE,
            CollectionFeature.ALLOWS_NULL_VALUES,
            CollectionFeature.KNOWN_ORDER,
            CollectionSize.ANY)

          parentBuilder) {
    return SetTestSuiteBuilder.using(
            new MultimapGetGenerator<K, V>(parentBuilder.getSubjectGenerator()))
        .withFeatures(computeMultimapGetFeatures(parentBuilder.getFeatures()))
        .named(parentBuilder.getName() + ".get[key]")
        .suppressing(parentBuilder.getSuppressedTests())
        .createTestSuite();
  }

  @Override