docs: def _format_links_fields(self, links):
          """
          Format the fields containing links into 4-tuples printable by _print_fields().
          """
          fields = list()
          for link in links:
              linked_model = link['mdl'](super_context)
              null = self._marker_true if link['null'] is True else self._marker_false
              # In LinkProxy, if reverse_name is empty then only reverse has the name
              # of the field on the link_source side
              field_name = link['field'] or link['reverse']
              fields.append((self._field_prefix, field_name, '%s()' % linked_model.title, null))
          fields.sort(key=lambda f: f[1])
          return fields