text: from django.core import checks
  from django.db import models
  
  
  class ModelRaisingMessages(models.Model):
      @classmethod
      def check(self, **kwargs):
          return [
              checks.Warning('First warning', hint='Hint', obj='obj'),
              checks.Warning('Second warning', obj='a'),
              checks.Error('An error', hint='Error hint'),
          ]
  