code: def ensure_has_same_campaigns(self):
          
          lhs_yaml = osp.join(self.lhs, 'campaign.yaml')
          rhs_yaml = osp.join(self.rhs, 'campaign.yaml')
          assert osp.isfile(lhs_yaml)
          assert osp.isfile(rhs_yaml)
          assert filecmp.cmp(lhs_yaml, rhs_yaml)
docs: Ensure that the 2 campaigns to merge have been generated
          from the same campaign.yaml