text: from django.db.models import (
      Model,
      BooleanField,
      CharField,
      TextField
  )
  
  from .mixins import MessagesMixin
  
  
  class RelevancyBaseModel(Model, MessagesMixin):
      is_relevant = BooleanField(
          default=False
      )
      relevancy_exception = CharField(
          blank=True,
          max_length=255,
          verbose_name='exception'
      )
  
      @property
      def may_be_relevant(self):
          return True
  
      @property
      def relevancy_warnings(self):
          return ''
      relevancy_warnings.fget.short_description = 'warnings'
  
      @property
      def relevancy_errors(self):
          return ''
      relevancy_errors.fget.short_description = 'errors'
  
      class Meta:
          abstract = True
  
  
  class NotesBaseModel(Model, MessagesMixin):
      notes = TextField(
          blank=True
      )
  
      class Meta:
          abstract = True
  