*
   * @throws IllegalArgumentException if {@code n < 0}
   */
  public static int factorial(int n) {
    checkNonNegative("n", n);
    return (n < factorials.length) ? factorials[n] : Integer.MAX_VALUE;
  }

  private static final int[] factorials = {
    1,
    1,
    1 * 2,
    1 * 2 * 3,
    1 * 2 * 3 * 4,
    1 * 2 * 3 * 4 * 5,
    1 * 2 * 3 * 4 * 5 * 6,

    final ImmutableList<E> inputList;

    PermutationCollection(ImmutableList<E> input) {
      this.inputList = input;
    }

    @Override
    public int size() {
      return IntMath.factorial(inputList.size());
    }

    @Override
    public boolean isEmpty() {
      return false;
    }

    @Override
    public Iterator<List<E>> iterator() {

    final ImmutableList<E> inputList;

    PermutationCollection(ImmutableList<E> input) {
      this.inputList = input;
    }

    @Override
    public int size() {
      return IntMath.factorial(inputList.size());
    }

    @Override
    public boolean isEmpty() {
      return false;
    }

    @Override
    public Iterator<List<E>> iterator() {

   *
   * @throws IllegalArgumentException if {@code n < 0}
   */
  @GwtIncompatible // TODO
  public static long factorial(int n) {
    checkNonNegative("n", n);
    return (n < factorials.length) ? factorials[n] : Long.MAX_VALUE;
  }

  static final long[] factorials = {
    1L,
    1L,
    1L * 2,
    1L * 2 * 3,
    1L * 2 * 3 * 4,
    1L * 2 * 3 * 4 * 5,
    1L * 2 * 3 * 4 * 5 * 6,

    final Map<String, ToolchainFactory> factories;

    @Inject
    public DefaultToolchainManager(Map<String, ToolchainFactory> factories) {
        this.factories = factories;
        this.logger = LoggerFactory.getLogger(DefaultToolchainManager.class);
    }

    /**
     * Ctor needed for UT.
     */
    DefaultToolchainManager(Map<String, ToolchainFactory> factories, Logger logger) {
        this.factories = factories;

    if (cls.isEnum()) {
      return;
    }
    List<? extends Invokable<?, ?>> factories = Lists.reverse(getFactories(TypeToken.of(cls)));
    if (factories.isEmpty()) {
      return;
    }
    int numberOfParameters = factories.get(0).getParameters().size();
    List<ParameterNotInstantiableException> paramErrors = Lists.newArrayList();

    if (cls.isEnum()) {
      return;
    }
    List<? extends Invokable<?, ?>> factories = Lists.reverse(getFactories(TypeToken.of(cls)));
    if (factories.isEmpty()) {
      return;
    }
    int numberOfParameters = factories.get(0).getParameters().size();
    List<ParameterNotInstantiableException> paramErrors = Lists.newArrayList();

    void setUp() {

        MockitoAnnotations.initMocks(this);

        Map<String, ToolchainFactory> factories = new HashMap<>();
        factories.put("basic", toolchainFactory_basicType);
        factories.put("rare", toolchainFactory_rareType);
        toolchainManager = new DefaultToolchainManagerPrivate(factories, logger);
    }

    @Test
    void testToolchainsForAvailableType() throws Exception {
        // prepare

    @Inject
    public DefaultToolchainManagerPrivate(Map<String, ToolchainFactory> factories) {
        super(factories);
    }

    /**
     * Ctor needed for UT.
     */
    DefaultToolchainManagerPrivate(Map<String, ToolchainFactory> factories, Logger logger) {
        super(factories, logger);
    }

    @Override

    void onSetup() throws Exception {
        MockitoAnnotations.initMocks(this);

        Map<String, ToolchainFactory> factories = new HashMap<>();
        factories.put("basic", toolchainFactory_basicType);
        factories.put("rare", toolchainFactory_rareType);
        toolchainManager = new DefaultToolchainManager(factories, logger);
    }

    @Test
    void testNoModels() {
        MavenSession session = mock(MavenSession.class);