VcapServicesStringSupplier implements Supplier<Optional<String>> { static VcapServicesStringSupplier of(final Path path) { return new VcapServicesStringSupplier(checkNotNull(path, "path of VCAP services (JSON) file")); } private  VcapServicesStringSupplier(final Path theVcapServicesFilePath); @Override Optional<String> get();  }
@Test public void tryToGetInstanceWithNullPath() { assertThatNullPointerException() .isThrownBy(() -> VcapServicesStringSupplier.of(null)) .withMessage("The path of VCAP services (JSON) file must not be null!") .withNoCause(); }