public void addProperty(String key, String value) {
        store.put(key, value);
    }
@Test
    void testIllegalType() {
        memConfig.addProperty("it", "aaa");

        Assertions.assertThrows(IllegalStateException.class, () -> memConfig.getInteger("it", 1));
        Assertions.assertThrows(IllegalStateException.class, () -> memConfig.getInt("it", 1));
        Assertions.assertThrows(IllegalStateException.class, () -> memConfig.getInt("it"));
    }