@Override
    public ConfigData get(String path) {
        return get(path, null);
    }
@Test
    public void testGetOneKeyWithNullPath() {
        ConfigData config = envVarConfigProvider.get(null, Collections.singleton("secret_var2"));
        Map<String, String> data = config.data();

        assertEquals(1, data.size());
        assertEquals("value2", data.get("secret_var2"));
    }