Scalr\Service\Aws\Ec2\V20150415\Ec2Api::describeInstances PHP Method

    public function describeInstances(ListDataType $instanceIdList = null, InstanceFilterList $filter = null, $nextToken = null, $maxResults = null)
    {
        $result = null;
        $options = [];
        if ($instanceIdList !== null) {
            $options = array_merge($options, $this->getInstanceIdListQuery($instanceIdList));
        }
        if ($filter !== null) {
            $options = array_merge($options, $filter->getQueryArrayBare('Filter'));
        }
        if ($nextToken !== null) {
            $options['NextToken'] = (string) $nextToken;
        }
        if ($maxResults !== null) {
            $options['MaxResults'] = (int) $maxResults;
        }
        $response = $this->client->call(ucfirst(__FUNCTION__), $options);
        if ($response->getError() === false) {
            //Success
            $sxml = simplexml_load_string($response->getRawContent());
            $response = null;
            $result = new ReservationList();
            $result->setEc2($this->ec2);
            $result->setRequestId((string) $sxml->requestId);
            $result->setNextToken($this->exist($sxml->nextToken) ? (string) $sxml->nextToken : null);
            if (!empty($sxml->reservationSet->item)) {
                foreach ($sxml->reservationSet->item as $r) {
                    $item = new ReservationData();
                    $item->setEc2($this->ec2);
                    $item->reservationId = (string) $r->reservationId;
                    $item->ownerId = $this->exist($r->ownerId) ? (string) $r->ownerId : null;
                    $item->requesterId = $this->exist($r->requesterId) ? (string) $r->requesterId : null;
                    $item->setGroupSet($this->_loadGroupList($r->groupSet))->setInstancesSet($this->_loadInstanceList($r->instancesSet));
                    $result->append($item);
                    unset($item);
                }
            }
        }
        return $result;
    }