old_contents: from springfield_mongo.entities import Entity as MongoEntity
  from springfield_mongo import utils
  from springfield import fields
  from bson.objectid import ObjectId
  
  
  # This dummy class just used to have an extra attribute to verify during
  # using the utils
  class FooEntity(MongoEntity):
      foo = fields.StringField()
  
  
  def test_entity_to_mongo():
      i = ObjectId()
      m = FooEntity()
      m.id = i
      m.foo = 'monkey'
  
      mongo_document = utils.entity_to_mongo(m)
      assert '_id' in mongo_document
      assert mongo_document['_id'] == i
      assert 'foo' in mongo_document
      assert mongo_document['foo'] == 'monkey'
  
  
  def test_entity_from_mongo():
      i = ObjectId()
      m = FooEntity()
      m.id = i
      m.foo = 'gorilla'
  
      mongo_document = utils.entity_to_mongo(m)
      entity = utils.entity_from_mongo(FooEntity, mongo_document)
      assert '_id' not in entity
      assert 'id' in entity
      assert entity['id'] == i
      assert 'foo' in entity
      assert entity['foo'] == 'gorilla'
  
  
  def test_to_and_from_equality():
      i = ObjectId()
      m = FooEntity()
      m.id = i
      m.foo = 'giraffe'
  
      mongo_document = utils.entity_to_mongo(m)
      entity = utils.entity_from_mongo(FooEntity, mongo_document)
      assert m == entity
      mongo_document2 = utils.entity_to_mongo(entity)
      assert mongo_document2 == mongo_document
  
new_contents: from springfield_mongo import utils
  from springfield_mongo.fields import ObjectIdField
  from springfield import fields
  from springfield import Entity
  from bson.objectid import ObjectId
  
  
  # This dummy class just used to have an extra attribute to verify during
  # using the utils
  class FooEntity(Entity):
      id = ObjectIdField()
      foo = fields.StringField()
  
  
  def test_entity_to_mongo():
      i = ObjectId()
      m = FooEntity()
      m.id = i
      m.foo = 'monkey'
  
      mongo_document = utils.entity_to_mongo(m)
      assert '_id' in mongo_document
      assert mongo_document['_id'] == i
      assert 'foo' in mongo_document
      assert mongo_document['foo'] == 'monkey'
  
  
  def test_entity_from_mongo():
      i = ObjectId()
      m = FooEntity()
      m.id = i
      m.foo = 'gorilla'
  
      mongo_document = utils.entity_to_mongo(m)
      entity = utils.entity_from_mongo(FooEntity, mongo_document)
      assert '_id' not in entity
      assert 'id' in entity
      assert entity['id'] == i
      assert 'foo' in entity
      assert entity['foo'] == 'gorilla'
  
  
  def test_to_and_from_equality():
      i = ObjectId()
      m = FooEntity()
      m.id = i
      m.foo = 'giraffe'
  
      mongo_document = utils.entity_to_mongo(m)
      entity = utils.entity_from_mongo(FooEntity, mongo_document)
      assert m == entity
      mongo_document2 = utils.entity_to_mongo(entity)
      assert mongo_document2 == mongo_document
  
subject: Update tests to reflect removal of springfield_mongo Entity.