code: public List<GitlabDiscussion> getDiscussions(GitlabMergeRequest mergeRequest) throws IOException {
          String tailUrl = GitlabProject.URL + "/" + mergeRequest.getProjectId() +
                  GitlabMergeRequest.URL + "/" + mergeRequest.getIid() +
                  GitlabDiscussion.URL;
  
          GitlabDiscussion[] discussions = retrieve().to(tailUrl, GitlabDiscussion[].class);
          return Arrays.asList(discussions);
      }
docs: Get the discussions from a merge request.
  <a href="https://docs.gitlab.com/ce/api/discussions.html#list-project-merge-request-discussions">https://docs.gitlab.com/ce/api/discussions.html#list-project-merge-request-discussions</a>
  
  @param mergeRequest to fetch the discussions from.
  
  @return The discussions contained in the given merge request.
  @throws IOException on a GitLab api call error