assertTrue(result.startsWith("\"dateKey\":\""));
        // Check that the date was converted to string and properly escaped
        assertTrue(result.contains("2021") || result.contains("Jan") || result.contains("1609459200000"));
    }

    // Test appendTimestamp method
    @Test
    public void test_appendTimestamp() {
        StringBuilder buf = new StringBuilder();

\u092c\u0930\u094d\u0937",yy:"%d \u092c\u0930\u094d\u0937"},week:{dow:0,doy:6}});var tr="jan._feb._mrt._apr._mei_jun._jul._aug._sep._okt._nov._dec.".split("_"),sr="jan_feb_mrt_apr_mei_jun_jul_aug_sep_okt_nov_dec".split("_"),nr=[/^jan/i,/^feb/i,/^maart|mrt.?$/i,/^apr/i,/^mei$/i,/^jun[i.]?$/i,/^jul[i.]?$/i,/^aug/i,/^sep/i,/^okt/i,/^nov/i,/^dec/i],rr=/^(januari|februari|maart|april|mei|ju[nl]i|augustus|september|oktober|november|december|jan\.?|feb\.?|mrt\.?|apr\.?|ju[nl]\.?|aug\.?|sep\.?|okt\.?|nov\.?|dec\.?)/i;M...