old_contents: from openfisca_core.model_api import Variable, Reform, MONTH
  from openfisca_country_template.entities import Person
  
  
  class goes_to_school(Variable):
      value_type = bool
      default_value = True
      entity = Person
      label = "The person goes to school (only relevant for children)"
      definition_period = MONTH
  
  
  class add_variable_reform(Reform):
      def apply(self):
          self.add_variable(goes_to_school)
  
new_contents: from openfisca_core.model_api import Variable, Reform, MONTH
  from openfisca_country_template.entities import Person
  
  
  def test_dynamic_variable():
      class NewDynamicClass(Variable):
          value_type = bool
          default_value = True
          entity = Person
          label = "The person goes to school (only relevant for children)"
          definition_period = MONTH
  
      NewDynamicClass.__name__ = "goes_to_school"
      return NewDynamicClass
  
  
  class add_variable_reform(Reform):
      def apply(self):
          self.add_variable(test_dynamic_variable())
  
subject: Update test reform to make it fail without a fix