public function getCampaigns($strAccountSlug, $intPage = 1, $intLimit = 10, $strFilter = null, $strSort = null) {
        $objWebClient = $this->getWebClient();

        $strUri = $this->getApiUrl() . '/accounts/' . $strAccountSlug . '/campaigns';
        $arrHeaders = $this->getHeaders();
        $strFilter = array('query' => array('page' => $intPage, 'limit' => $intLimit, 'filter' => $strFilter, 'sort' => $strSort));

        $objRequest = $objWebClient->get($strUri, $arrHeaders, $strFilter);

        $this->objResponse = $objRequest->send();
        $strResponse = $this->objResponse->getBody(TRUE);

        return $strResponse;
    }