* and will cause {@link #build} to fail.
     */
    @CanIgnoreReturnValue
    public <T extends B> Builder<B> put(TypeToken<T> key, T value) {
      mapBuilder.put(key.rejectTypeVariables(), value);
      return this;
    }

    /**
     * Returns a new immutable type-to-instance map containing the entries provided to this builder.
     *

    return trustedGet(TypeToken.of(type));
  }

  @Override
  @CheckForNull
  public <T extends @NonNull B> T getInstance(TypeToken<T> type) {
    return trustedGet(type.rejectTypeVariables());
  }

  @Override
  @CanIgnoreReturnValue
  @CheckForNull
  public <T extends B> T putInstance(Class<@NonNull T> type, @ParametricNullness T value) {
    return trustedPut(TypeToken.of(type), value);
  }

  private static void assertHasTypeVariable(Type type) {
    try {
      TypeToken.of(type).rejectTypeVariables();
      fail("Should contain TypeVariable");
    } catch (IllegalArgumentException expected) {
    }
  }

  private static void assertNoTypeVariable(Type type) {
    TypeToken.of(type).rejectTypeVariables();
  }

  private static void assertHasTypeVariable(Type type) {
    try {
      TypeToken.of(type).rejectTypeVariables();
      fail("Should contain TypeVariable");
    } catch (IllegalArgumentException expected) {
    }
  }

  private static void assertNoTypeVariable(Type type) {
    TypeToken.of(type).rejectTypeVariables();
  }

  /**
   * Ensures that this type token doesn't contain type variables, which can cause unchecked type
   * errors for callers like {@link TypeToInstanceMap}.
   */
  @CanIgnoreReturnValue
  final TypeToken<T> rejectTypeVariables() {
    new TypeVisitor() {
      @Override
      void visitTypeVariable(TypeVariable<?> type) {
        throw new IllegalArgumentException(