// ----------------------------------------------------------
  public WOComponent repartner() {
    for (UserSubmissionPair pair : userGroup().allObjects()) {
      Submission sub = pair.submission();

      if (sub != null && sub.result() != null) {
        for (Submission psub : sub.result().submissions()) {
          if (psub != sub
              && psub.assignmentOffering().assignment() != sub.assignmentOffering().assignment()) {
            log.warn(
                "found partner submission "
                    + psub.user()
                    + " #"
                    + psub.submitNumber()
                    + "\non incorrect assignment offering "
                    + psub.assignmentOffering());

            NSArray<AssignmentOffering> partnerOfferings =
                AssignmentOffering.objectsMatchingQualifier(
                    localContext(),
                    AssignmentOffering.courseOffering
                        .dot(CourseOffering.course)
                        .eq(sub.assignmentOffering().courseOffering().course())
                        .and(
                            AssignmentOffering.courseOffering
                                .dot(CourseOffering.students)
                                .eq(psub.user()))
                        .and(
                            AssignmentOffering.assignment.eq(
                                sub.assignmentOffering().assignment())));
            if (partnerOfferings.count() == 0) {
              log.error(
                  "Cannot locate correct assignment "
                      + "offering for partner"
                      + psub.user()
                      + " #"
                      + psub.submitNumber()
                      + "\non incorrect assignment offering "
                      + psub.assignmentOffering());
            } else {
              if (partnerOfferings.count() > 1) {
                log.warn(
                    "Multiple possible offerings for "
                        + "partner "
                        + psub.user()
                        + " #"
                        + psub.submitNumber()
                        + "\non incorrect assignment offering "
                        + psub.assignmentOffering());
                for (AssignmentOffering ao : partnerOfferings) {
                  log.warn("\t" + ao);
                }
              }

              psub.setAssignmentOfferingRelationship(partnerOfferings.get(0));
            }
          }
        }
      }
    }
    applyLocalChanges();
    return null;
  }