public function requestCampaign($id, $leads, $tokens = array(), $args = array(), $returnRaw = false)
    {
        $args['id'] = $id;

        $args['input'] = array('leads' => array_map(function ($id) {
            return array('id' => $id);
        }, (array) $leads));

        if (!empty($tokens)) {
            $args['input']['tokens'] = $tokens;
        }

        return $this->getResult('requestCampaign', $args, false, $returnRaw);
    }