text: from datavalidation import data_validator, PASS, FAIL, NA, Summary
  from datavalidation.models import DataValidationMixin
  
  from .base import BaseModel
  
  
  class CReturnValues(DataValidationMixin, BaseModel):
      """ Class Method Data Validator Return Values
  
      tests: valid return values for class method validators
      """
      @data_validator
      @classmethod
      def returning_result(cls):
          """ tests: returning PASS/FAIL """
          if cls.objects.filter(foobar__gte=10).count() == 0:
              return PASS
          return FAIL
  
      @data_validator
      @classmethod
      def returning_bool(cls):
          """ tests: returning a bool """
          return cls.objects.filter(foobar__gte=10).count() == 0
  
      @data_validator
      @classmethod
      def returning_queryset(cls):
          """ tests: returning a queryset """
          return cls.objects.filter(foobar__gte=10)
  
      @data_validator
      @classmethod
      def returning_list_of_models(cls):
          """ tests: returning a list """
          return list(cls.objects.filter(foobar__gte=10))
  
      @data_validator
      @classmethod
      def returning_list_of_model_ids(cls):
          """ tests: returning a list of ids """
          return cls.objects.filter(foobar__gte=10).values_list("id", flat=True)
  
      @data_validator
      @classmethod
      def returning_summary(cls):
          return Summary(
              num_passing=cls.objects.filter(foobar__lt=10).count(),
              num_na=cls.objects.filter(foobar__isnull=True).count(),
              failures=cls.objects.filter(foobar__gte=10)
          )
  
      @data_validator
      @classmethod
      def returning_bad_summary(cls):
          return Summary(
              failures=True  # noqa
          )
  
      @data_validator
      @classmethod
      def returning_na(cls):
          """ tests: returning NA (exception expected) """
          return NA
  
      @data_validator
      @classmethod
      def returning_none(cls):
          """ tests: returning None (exception expected) """
          return None
  
      @data_validator
      @classmethod
      def raising_exception(cls):
          """ tests: raising an exception """
          raise ValueError("An Error!")
  