public static Caffeine<Object, Object> from(CaffeineSpec spec) {
    Caffeine<Object, Object> builder = spec.toBuilder();
    builder.strictParsing = false;
    return builder;
  }
@Test
  public void fromSpec_null() {
    assertThrows(NullPointerException.class, () -> Caffeine.from((CaffeineSpec) null));
  }