text: from marshmallow.base import FieldABC
  from marshmallow.fields import Nested, Field
  from marshmallow_jsonapi.fields import Relationship as GenericRelationship, BaseRelationship
  
  from combojsonapi.utils import Relationship
  
  
  class TestRelationship:
      def test_mro(self):
          assert Relationship.mro() == [Relationship,
                                        GenericRelationship,
                                        BaseRelationship,
                                        Nested,
                                        Field,
                                        FieldABC,
                                        object]
  