docs: def save(self, *args, **kwargs):
          """
          Fill 'created' and 'modified' attributes on first create and allways update 
          the thread's 'modified' attribute
          """
          edited = not(self.created is None)
          
          if self.created is None:
              self.created = tz_now()
          
          # Update de la date de modif. du message
          if self.modified is None:
              self.modified = self.created
          else:
              self.modified = tz_now()
          
          super(Post, self).save(*args, **kwargs)
          
          # Update de la date de modif. du thread lors de la création du message
          if not edited:
              self.thread.modified = self.created
              self.thread.save()