public void isAssignableTo(Class<?> clazz) {
    if (!clazz.isAssignableFrom(checkNotNull(actual))) {
      failWithActual("expected to be assignable to", clazz.getName());
    }
  }
@Test
  public void testIsAssignableTo_same() {
    assertThat(String.class).isAssignableTo(String.class);
  }