#vulnerable code 
                                private boolean isServiceUndeployed(int environmentId, int serviceId){
        Date latestDeploymentDate = getLatestDeploymentDateByServiceIdInEnvironment(environmentId, serviceId);
        Date latestUpdatedDate = getLatestDeployableVersionDateByServiceId(serviceId);

        if(latestDeploymentDate != null) {
            long diffBetweenDatesInDays = TimeUnit.DAYS.convert(Math.abs(latestDeploymentDate.getTime() - latestUpdatedDate.getTime()), TimeUnit.MILLISECONDS);
            return diffBetweenDatesInDays > MIN_DAYS_OF_UNDEPLOYED_SERVICES ? true : false;
        }
        if(latestUpdatedDate != null) {
            Date durationSinceLatestUpdate = Date.from(LocalDate.now().minusDays((long) MIN_DAYS_OF_UNDEPLOYED_SERVICES).atStartOfDay(ZoneId.systemDefault()).toInstant());
            if(latestUpdatedDate.compareTo(durationSinceLatestUpdate) < 0) {
                return true;
            }
        }
        return false;
    } 
                            #location 6 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                private boolean isServiceUndeployed(int environmentId, int serviceId){
        Date latestDeploymentDate = getLatestDeploymentDateByServiceIdInEnvironment(environmentId, serviceId);
        Date latestUpdatedDate = getLatestDeployableVersionDateByServiceId(serviceId);

        if(latestDeploymentDate != null) {
            long diffBetweenDatesInDays = getTimeDiffInDays(latestDeploymentDate, latestUpdatedDate);
            return diffBetweenDatesInDays > MAX_DAYS_OF_UNDEPLOYED_SERVICES ? true : false;
        }
        if(latestUpdatedDate != null) {
            Date maxDateSinceLatestUpdate = getMaxDateSinceLatestUpdate();
            if(latestUpdatedDate.compareTo(maxDateSinceLatestUpdate) < 0) {
                return true;
            }
        }
        return false;
    }