When\When::getPrevOccurrence PHP Method

    public function getPrevOccurrence($occurDate)
    {
        self::prepareDateElements(false);
        $startDate = $this->startDate;
        $candidates = $this->getOccurrencesBetween($startDate, $occurDate);
        if (count($candidates)) {
            $lastDate = array_pop($candidates);
            if ($lastDate == $occurDate) {
                $lastDate = array_pop($candidates);
            }
            return $lastDate;
        }
        return false;
    }

 function testGetPrevOccurrenceFromFirstOccurence()
 {
     $r = new When();
     $r->startDate(new DateTime("19970902T090000"))->rrule("FREQ=WEEKLY")->until(new DateTime("19971104T090000"));
     $result = $r->getPrevOccurrence(new DateTime("19970902T090000"));
     $this->assertFalse($result);
 }