assertWithMessage("%s to %s", from, to).that(from.to(to, " ")).isEqualTo(" ");
      }
    }
  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testNullArguments() {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicStaticMethods(CaseFormat.class);
    for (CaseFormat format : CaseFormat.values()) {
      tester.testAllPublicInstanceMethods(format);