docs: def _model_relations(ins):
      """ Get relationships info
  
      :type ins: sqlalchemy.orm.mapper.Mapper
      :rtype: list[SaRelationshipDoc]
      """
      relations = []
      for r in ins.relationships:
          # Hard times with the foreign model :)
          if isinstance(r.argument, Mapper):
              model_name = r.argument.class_.__name__
          elif hasattr(r.argument, 'arg'):
              model_name = r.argument.arg
          else:
              model_name = r.argument.__name__
  
          # Format
          relations.append(SaRelationshipDoc(
              key=r.key,
              doc=r.doc or '',
              model=model_name,
              pairs=map(lambda a_b_tuple: a_b_tuple[0].key if a_b_tuple[0].key == a_b_tuple[1].key else '{}={}'.format(a_b_tuple[0].key, a_b_tuple[1].key), r.local_remote_pairs),
              uselist=r.uselist
          ))
      return relations