public static Gson instance() {
        return SingletonHolder.INSTANCE;
    }
@Test
    void serializesFiles() {
        File file = new File("/hello/world");
        assertThatJson(Serialization.instance().toJson(file))
                .isEqualTo(format("{\"path\":\"%s\"}", escapeJson(separatorsToSystem(file.getPath()))));
    }