@Test
    void calculatePatternDefault() {
        setupValues(null, Locale.ENGLISH);
        assertEquals("M/d/yyyy", datePicker.calculatePattern());
    }
Invalid {@link ResolverStyle}. The date 02/30/2019 is silently parsed to
02/28/2019 as default value 'SMART' is used.
primefaces/src/test/java/org/primefaces/component/datepicker/DatePickerTest.java