public function testGetCampaignReturnsCorrectData()
 {
     $this->setMockResponse($this->client, array('campaigns/getCampaign'));
     $campaign = $this->client->getCampaign(1);
     $this->assertInstanceOf('\\Mgrt\\Model\\Campaign', $campaign);
     $mailingLists = $campaign->getMailingLists();
     foreach ($mailingLists as $mailingList) {
         $this->assertInstanceOf('\\Mgrt\\Model\\MailingList', $mailingList);
     }
 }