old_contents: from django.db import models
  
  # Create your models here.
  
new_contents: from django.db import models
  from django.contrib.auth.models import User
  from fsmedhrocore.models import BasicHistory
  
  
  class Kunde(BasicHistory):
      """
      Extends django.contrib.auth.models.User if already registered
      """
      user = models.OneToOneField(User, blank=True, null=True)  # optional link to fsmedhro-User
  
      anschrift = models.CharField(max_length=255, blank=True, null=True)
      bemerkung = models.TextField(blank=True, null=True)
      tel = models.CharField(max_length=16, blank=True, null=True)
  
      # old information. Will be ignored if 'user' is set
      kunden_id = models.PositiveIntegerField(blank=True, null=True)
      kunden_name = models.CharField(max_length=30, blank=True, null=True)
      kunden_vorname = models.CharField(max_length=30, blank=True, null=True)
      kunden_email = models.CharField(max_length=30, blank=True, null=True)
      # geschlecht_id_f = models.ForeignKey(Tblgeschlecht)
      # studg_id_f = models.ForeignKey(Tblstudiengang)
      # kunden_timestamp = models.DateTimeField()
  
      def __str__(self):
          """
          returns "[Vorname] [Nachname]"
          """
          if self.user:
              return self.user.get_full_name()
          else:
              full_name = '%s %s' % (self.kunden_vorname, self.kunden_name)
              return full_name.strip()
  
      class Meta:
          verbose_name = "Kundin/Kunde"
          verbose_name_plural = "Kundinnen/Kunden"
subject: add model 'Kunde'