code: public GitlabDiscussion createDiscussion(GitlabMergeRequest mergeRequest,
              String body, String positionBaseSha, String positionStartSha,
              String positionHeadSha) throws IOException {
          return createTextDiscussion(mergeRequest, body, null,
                  positionBaseSha, positionStartSha, positionHeadSha,
                  null, null, null, null);
      }
docs: Create a discussion just with the required arguments.
  
  @param mergeRequest      The merge request where the discussion is created.
  @param body              The content of a discussion.
  @param positionBaseSha   The base commit SHA in the source branch.
  @param positionStartSha  The SHA referencing the commit in the target branch.
  @param positionHeadSha   The SHA referencing the HEAD of this merge request.
  
  @return The created discussion object.
  @throws IOException on a GitLab api call error