Class<T> type = (Class<T>) runtimeType;
      return of(Primitives.wrap(type));
    }
    return this;
  }

  private boolean isWrapper() {
    return Primitives.allWrapperTypes().contains(runtimeType);
  }

  /**
   * Returns the corresponding primitive type if this is a wrapper type; otherwise returns {@code
   * this} itself. Idempotent.
   *
   * @since 15.0
   */

  public <T extends Integer> void testPrimitiveWrappingAndUnwrapping() {
    for (Class<?> type : Primitives.allPrimitiveTypes()) {
      assertIsPrimitive(TypeToken.of(type));
    }
    for (Class<?> type : Primitives.allWrapperTypes()) {
      assertIsWrapper(TypeToken.of(type));
    }
    assertNotPrimitiveNorWrapper(TypeToken.of(String.class));
    assertNotPrimitiveNorWrapper(TypeToken.of(Object[].class));

  public <T extends Integer> void testPrimitiveWrappingAndUnwrapping() {
    for (Class<?> type : Primitives.allPrimitiveTypes()) {
      assertIsPrimitive(TypeToken.of(type));
    }
    for (Class<?> type : Primitives.allWrapperTypes()) {
      assertIsWrapper(TypeToken.of(type));
    }
    assertNotPrimitiveNorWrapper(TypeToken.of(String.class));
    assertNotPrimitiveNorWrapper(TypeToken.of(Object[].class));