old_contents: from django.db import models
  from django.contrib.auth.models import Group, User
  
  class Depot(models.Model):
      """
      Model a depot.
      A depot has a name and many depot managers.
  
      :author: Leo Tappe
      """
      name = models.CharField(max_length=256)
      managers = models.ManyToManyField(User)
  
      def __str__(self):
          return "Depot %s" % self.name
  
  class Item(models.Model):
      """
      Model an item.
      An item has a name.
      Quantity: how many versions of this item exist.
      An item has different visibility levels, which determine who can view them.
      An item is in a depot.
      An item has a specific location within its depot.
  
      :author: Leo Tappe
      """
      VISIBILITY_PUBLIC = '1'
      VISIBILITY_PRIVATE = '2'
      VISIBILITY_LEVELS = (
          (VISIBILITY_PUBLIC, 'public'),
          (VISIBILITY_PRIVATE, 'private'),
      )
      name = models.CharField(max_length=256)
      quantity = models.IntegerField()
      visibility = models.CharField(max_length=1, choices=VISIBILITY_LEVELS)
      depot = models.ForeignKey(Depot, on_delete=models.CASCADE)
      location = models.CharField(max_length=256)
  
      def __str__(self):
          return '%s unit(s) of %s (visib.: %s) in %s' % (self.quantity, self.name, self.visibility, self.location)
  
new_contents: from django.db import models
  from django.contrib.auth.models import Group, User
  
  class Depot(models.Model):
      """
      Model a depot.
      A depot has a name and many depot managers.
  
      :author: Leo Tappe
      """
      name = models.CharField(max_length=256)
      managers = models.ManyToManyField(User)
  
      def __str__(self):
          return "Depot %s" % self.name
  
  class Item(models.Model):
      """
      Model an item.
      An item has a name.
      Quantity: how many versions of this item exist.
      An item has different visibility levels, which determine who can view them.
      An item is in a depot.
      An item has a specific location within its depot.
  
      :author: Leo Tappe
      """
      VISIBILITY_PUBLIC = '1'
      VISIBILITY_PRIVATE = '2'
      VISIBILITY_LEVELS = (
          (VISIBILITY_PUBLIC, 'public'),
          (VISIBILITY_PRIVATE, 'private'),
      )
      name = models.CharField(max_length=256)
      quantity = models.IntegerField()
      visibility = models.CharField(max_length=1, choices=VISIBILITY_LEVELS)
      depot = models.ForeignKey(Depot, on_delete=models.CASCADE)
      location = models.CharField(max_length=256)
  
      def __str__(self):
          return ('%s unit(s) of %s (visib.: %s) in %s'
                  % (self.quantity, self.name, self.visibility, self.location))
subject: Add line break