void.class);

    assertThrows(UnsupportedOperationException.class, () -> primitives.remove(boolean.class));
  }

  public void testAllWrapperTypes() {
    Set<Class<?>> wrappers = Primitives.allWrapperTypes();
    assertThat(wrappers)
        .containsExactly(
            Boolean.class,
            Byte.class,
            Character.class,
            Double.class,
            Float.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));