@Override
              public NavigableSet<String> create(String[] elements) {
                NavigableSet<String> innerSet = new TreeSet<>();
                Collections.addAll(innerSet, elements);
                return Collections.checkedNavigableSet(innerSet, String.class);
              }
            })
        .named("checkedNavigableSet/TreeSet, natural")
        .withFeatures(

        Set<File> filesToDelete = new HashSet<>();
        filesToDelete.addAll(collectFilesToDelete(classesToDelete, compileOutput));
        filesToDelete.addAll(collectFilesToDelete(classesToDelete, annotationProcessorOutput));
        filesToDelete.addAll(collectFilesToDelete(classesToDelete, headerOutput));
        filesToDelete.addAll(collectFilesToDelete(resourcesToDelete.get(CLASS_OUTPUT), compileOutput));

                compilers.addAll(findVisualCpps());
                compilers.add(findMinGW());
            } else if (OperatingSystem.current().isMacOsX()) {
                compilers.addAll(findClangs(true));
                compilers.addAll(findGccs(false));
                compilers.addAll(findSwiftcs());
            } else {
                compilers.addAll(findGccs(true));

    private <T> Collection<T> getExtensionComponents(Collection<MavenProject> projects, Class<T> role) {
        Collection<T> foundComponents = new LinkedHashSet<>();
        foundComponents.addAll(lookup.lookupList(role));
        foundComponents.addAll(getProjectScopedExtensionComponents(projects, role));
        return foundComponents;
    }

    def quiet(String... msgs) {
        quietMessages.addAll(msgs)
    }
    def error(String... msgs) {
        errorMessages.addAll(msgs)
    }
    def warning(String... msgs) {
        warningMessages.addAll(msgs)
    }
    def lifecycle(String... msgs) {
        warningMessages.addAll(msgs)
    }
    def info(String... msgs) {
        infoMessages.addAll(msgs)
    }
    def debug(String... msgs) {

                .addAll(additional.applicationClasspath)
                .addAll(additional.applicationModulepath)
                .build();
            List<TestFrameworkDistributionModule> additionalImplementationClasspath = ImmutableList.<TestFrameworkDistributionModule>builder()
                .addAll(additional.implementationClasspath)
                .addAll(additional.implementationModulepath)

            Set<MavenProject> selectedProjects = new HashSet<>(requiredSelectors.size() + optionalSelectors.size());
            selectedProjects.addAll(
                    projectSelector.getRequiredProjectsBySelectors(request, allSortedProjects, requiredSelectors));
            selectedProjects.addAll(
                    projectSelector.getOptionalProjectsBySelectors(request, allSortedProjects, optionalSelectors));

        final List<String> tagList = new ArrayList<>();
        for (final String tagFieldName : tagFieldNames) {
            tagList.addAll(Arrays.asList(SuggestUtil.parseQuery(queryString, tagFieldName)));
            if (filterQueryString != null) {
                tagList.addAll(Arrays.asList(SuggestUtil.parseQuery(filterQueryString, tagFieldName)));
            }
        }

        }
    }

    @Override
    public List<String> getCompilerDefines() {
        List<String> defines = new ArrayList<String>();
        defines.addAll(getDefines("cCompiler"));
        defines.addAll(getDefines("cppCompiler"));
        defines.addAll(getDefines("rcCompiler"));
        return defines;
    }

    @Override
    public LanguageStandard getLanguageStandard() {

      return this;
    }

    @CanIgnoreReturnValue
    @Override
    public Builder<E> addAll(Iterator<? extends E> elements) {
      super.addAll(elements);
      return this;
    }

    @CanIgnoreReturnValue
    Builder<E> combine(Builder<E> builder) {
      checkNotNull(builder);
      contents.addAll(builder.contents);
      return this;
    }

    @Override