assertEquals("timestamp:2023-01-01 timestamp:2023-12-31",
                getAsQuery(Collections.singletonMap(k, new String[] { "2023-01-01", "2023-12-31" })));
    }

    @Test
    public void test_conditions_occurrence() {
        final String k = "occt";
        assertEquals("allintitle:", getAsQuery(Collections.singletonMap(k, new String[] { "allintitle" })));