static Instant decimalEpochTimestampToSQLTimestamp(String timestamp)
    {
        long promTimestampMillis = (long) (Double.parseDouble(timestamp) * 1000);
        return ofEpochMilli(promTimestampMillis);
    }
@Test
    public void testDeserializeTimestamp()
    {
        Instant now = Instant.now();
        long nowEpochMillis = now.toEpochMilli();
        String nowTimeStr = PrometheusSplitManager.decimalSecondString(nowEpochMillis);
        Instant nowTimestampActual = PrometheusTimestampDeserializer.decimalEpochTimestampToSQLTimestamp(nowTimeStr);
        assertEquals(nowTimestampActual, now.truncatedTo(MILLIS));
    }