          serializer = ExcludedFieldSerializer()
          expected = dedent("""
              ExcludedFieldSerializer():
                  id = IntegerField(label='ID', read_only=True)
                  race_name = CharField(allow_null=True, max_length=100, required=False)
          """)
          assert repr(serializer) == expected
  
      def test_ignore_validation_for_null_fields(self):
          # None values that are on fields which are part of the uniqueness
 
</s> remove                 race_name = CharField(allow_null=True, max_length=100, required=True)
                position = IntegerField(allow_null=True, required=True)
 </s> add                 race_name = CharField(max_length=100, required=True)
                position = IntegerField(required=True) </s> remove     race_name = models.CharField(max_length=100, null=True)
    position = models.IntegerField(null=True)
 </s> add     race_name = models.CharField(max_length=100)
    position = models.IntegerField()
                race_name = CharField(max_length=100)
          serializer = ExcludedFieldSerializer()
          expected = dedent("""
              ExcludedFieldSerializer():
                  id = IntegerField(label='ID', read_only=True)
                race_name = CharField(max_length=100)
          """)
          assert repr(serializer) == expected
  
      def test_ignore_validation_for_null_fields(self):
          # None values that are on fields which are part of the uniqueness
keep keep keep keep replace keep keep keep keep keep
 Return UniquenessTogetherModel to previous state 
tests/test_validators.py