def _check_prepopulated_fields_value_item(self, obj, model, field_name, label):

        try:
            model._meta.get_field(field_name)
        except FieldDoesNotExist:
            return refer_to_missing_field(field=field_name, option=label, model=model, obj=obj, id='admin.E030')
        else:
            return []
For `prepopulated_fields` equal to {"slug": ("title",)},
dataset/ETHPy150Open django/django/django/contrib/admin/checks.py/BaseModelAdminChecks._check_prepopulated_fields_value_item