NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicInstanceMethods(Doubles.stringConverter());
  }

  @GwtIncompatible
  public void testTryParse_withNullNoGwt() {
    assertThat(Doubles.tryParse("null")).isNull();
    assertThrows(NullPointerException.class, () -> Doubles.tryParse(null));
  }