code: public Note createMergeRequestNote(Object projectIdOrPath, Integer mergeRequestIid, String body) throws GitLabApiException {
          GitLabApiForm formData = new GitLabApiForm().withParam("body", body, true);
          Response response = post(Response.Status.CREATED, formData,
                  "projects", getProjectIdOrPath(projectIdOrPath), "merge_requests", mergeRequestIid, "notes");
          return (response.readEntity(Note.class));
      }
docs: Create a merge request's note.
  
  @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
  @param mergeRequestIid  the merge request IID to create the notes for
  @param body the content of note
  @return the created Note instance
  @throws GitLabApiException if any exception occurs