new_contents: from __future__ import unicode_literals
  import sqlalchemy as sa
  from tests import TestCase
  from sqlalchemy_utils import batch_fetch, generic_relationship
  
  
  class TestBatchFetchGenericRelationship(TestCase):
      def create_models(self):
          class Building(self.Base):
              __tablename__ = 'building'
              id = sa.Column(sa.Integer, primary_key=True)
  
          class User(self.Base):
              __tablename__ = 'user'
              id = sa.Column(sa.Integer, primary_key=True)
  
          class Event(self.Base):
              __tablename__ = 'event'
              id = sa.Column(sa.Integer, primary_key=True)
  
              object_type = sa.Column(sa.Unicode(255))
              object_id = sa.Column(sa.Integer, nullable=False)
  
              object = generic_relationship(object_type, object_id)
  
          self.Building = Building
          self.User = User
          self.Event = Event
  
      def test_batch_fetch(self):
          user = self.User()
  
          self.session.add(user)
          self.session.commit()
          event = self.Event(object=user)
          self.session.add(event)
          self.session.commit()
  
          events = self.session.query(self.Event).all()
          batch_fetch(events, 'object')
          query_count = self.connection.query_count
          events[0].object
  
          assert self.connection.query_count == query_count
  
subject: Add tests for generic relationship batch fetching