code: public GitlabMergeRequestApprovals setMergeRequestApprovers(GitlabMergeRequest mr,
                                                                  Collection<Integer> userApproverIds,
                                                                  Collection<Integer> groupApproverIds) throws IOException {
          String tailUrl = GitlabProject.URL + "/" + sanitizeProjectId(mr.getProjectId()) +
                  GitlabMergeRequest.URL + "/" + mr.getIid() + GitlabMergeRequestApprovals.APPROVERS_URL;
          return put()
              .with("approver_ids", userApproverIds)
              .with("approver_group_ids", groupApproverIds)
              .to(tailUrl, GitlabMergeRequestApprovals.class);
      }
docs: Set the list of approvers.  Important: Approvers and groups not
  in the request will be removed
  
  EE only.