old_contents: from django.db import models
  
  from app.models.account import *
  
  
  class Shed(models.Model):
      name = models.CharField(max_length=100, unique=True, blank=False)
      registered_on = models.DateTimeField(auto_now_add=True)
  
      # Foreign keys
      owner = models.ForeignKey(User)
      address = models.ForeignKey(Address)
  
      @property
      def share_zone(self):
          return (self.address.zip[:5]).ljust(9, '0')
  
      class Meta:
          app_label = 'app'
  
      def __str__(self):
          return self.name
new_contents: from django.db import models
  
  from app.models.account import *
  
  
  class Shed(models.Model):
      name = models.CharField(max_length=100, unique=True, blank=False)
      registered_on = models.DateTimeField(auto_now_add=True)
  
      # Foreign keys
      owner = models.ForeignKey(User)
      address = models.ForeignKey(Address)
  
      @property
      def share_zone(self):
          return self.address.share_zone
  
      class Meta:
          app_label = 'app'
  
      def __str__(self):
          return self.name
subject: Change to share zone property of shed which follows new convention