old_contents: # -*- coding: utf-8 -*-
  
  from django.db import models
  
  from calebasse.personnes.models import People
  from calebasse.ressources.models import ServiceLinkedAbstractModel
  
  class PatientRecord(People, ServiceLinkedAbstractModel):
      class Meta:
          verbose_name = u'Dossier'
          verbose_name_plural = u'Dossiers'
  
      contacts = models.ManyToManyField('personnes.People',
              related_name='contact_of')
  
  
new_contents: # -*- coding: utf-8 -*-
  
  from django.db import models
  
  from calebasse.personnes.models import People
  from calebasse.ressources.models import ServiceLinkedAbstractModel
  
  class PatientRecord(ServiceLinkedAbstractModel, People):
      class Meta:
          verbose_name = u'Dossier'
          verbose_name_plural = u'Dossiers'
  
      contacts = models.ManyToManyField('personnes.People',
              related_name='contact_of')
  
  
subject: put mixin before parent class