public void GetCampaignsCampaignIdTest()
        {
            // TODO: add unit test for the method 'GetCampaignsCampaignId'
            string campaignId = null; // TODO: replace null with proper value
            var    response   = instance.GetCampaignsCampaignId(campaignId);

            Assert.IsInstanceOf <Campaign> (response, "response is Campaign");
        }