public void testIsWrapperType() {
    assertThat(Primitives.isWrapperType(Void.class)).isTrue();
    assertThat(Primitives.isWrapperType(void.class)).isFalse();
  }

  public void testWrap() {
    assertThat(Primitives.wrap(int.class)).isEqualTo(Integer.class);
    assertThat(Primitives.wrap(Integer.class)).isEqualTo(Integer.class);
    assertThat(Primitives.wrap(String.class)).isEqualTo(String.class);
  }