code: def by_causes(queryset, cause_string=None):
    
    if cause_string:
      operator, items = get_operator_and_items(cause_string)
      q_obj = SQ()
      for c in items:
        if len(c) > 0:
          q_obj.add(SQ(causes=c), operator)
      queryset = queryset.filter(q_obj)
    return queryset
docs: Filter queryset by a comma delimeted cause list