How to decouple GeoTargetWrapper from this function?

geotargeting.php

public function getGeotargetingPopulationData($requestBody)
    {
        return parent::processMessage(
            function () use ($requestBody)
            {
                $this->myPlaceLocal->authorization->validateLoggedInUser();

                if (empty($requestBody['geotargeting']) || empty($requestBody['impressions']))
                {
                    throw new InvalidApiParameterException("Expecting geo-targeting and impressions.");
                }

                $impressions    = $requestBody['impressions'];
                $impressionName = 'impressions';
                $params         = [$impressionName => $impressions];

                $this->apiValidator->setParams($params);
                $this->apiValidator->addRequiredParam($impressionName, 'positive');
                $this->apiValidator->validate();

                $this->campaignGeotargeting->fromAssociativeArray($requestBody['geotargeting']);

                $geoTargetWrapper = new GeoTargetWrapper();
                $geoTargetWrapper->transformFrom($this->campaignGeotargeting);
                $result = $this->geoTargetingServiceClient->getGeoTargetPopulation($geoTargetWrapper);

                $reachRatio = 0;
                if (!empty($result))
                {
                    $population = isset($result['total']) ? $result['total'] : 0;
                    $reachRatio = $population / $impressions;
                }

                $data = ["reachRatio" => $reachRatio];

                $this->apiResponse
                    ->setResult(true)
                    ->setStatusCode(ApiResponse::API_STATUS_SUCCESS)
                    ->setData($data)
                    ->setMessage('Reach ratio retrieved successfully.');

                return $this->apiResponse;
            }
        );
    }