public void clear() {
        params.clear();
        isEmpty = true;
    }
@Test
    void testClear() {
        Query query = Query.newInstance().addParam("key-1", "value-1").addParam("key-2", "value-2");
        assertFalse(query.isEmpty());
        assertEquals("value-1", query.getValue("key-1"));
        query.clear();
        assertTrue(query.isEmpty());
    }