Markdown::getYearMonthById PHP Method

    public function getYearMonthById($yearMonthId)
    {
        $cacheKey = "getYearMonthById_" . $yearMonthId . ".gb";
        $yearMonthObj = $this->gbReadCache($cacheKey);
        if ($yearMonthObj === false) {
            foreach ($this->yearMonths as $idx => $yearMonth) {
                if ($yearMonth['id'] == $yearMonthId) {
                    $yearMonthObj = $yearMonth;
                    $this->gbWriteCache($cacheKey, $yearMonthObj);
                    break;
                }
            }
        }
        return $yearMonthObj;
    }