old_contents: # -*- coding: utf-8 -*-
  from __future__ import unicode_literals
  
  from django.db import models, migrations
  
  
  class Migration(migrations.Migration):
  
      dependencies = [
          ('server', '0005_auto_20150717_1827'),
      ]
  
      operations = [
          migrations.AddField(
              model_name='machine',
              name='first_checkin',
              field=models.DateTimeField(auto_now_add=True, null=True),
          ),
          migrations.AddField(
              model_name='machine',
              name='sal_version',
              field=models.TextField(null=True, blank=True),
          ),
      ]
  
new_contents: # -*- coding: utf-8 -*-
  from __future__ import unicode_literals
  from django.shortcuts import get_object_or_404
  from django.db import models, migrations
  
  def add_initial_date(apps, schema_editor):
      Machine = apps.get_model("server", "Machine")
      for machine in Machine.objects.all():
          if not machine.first_checkin:
              machine.first_checkin = machine.last_checkin
              machine.save()
  
  class Migration(migrations.Migration):
  
      dependencies = [
          ('server', '0005_auto_20150717_1827'),
      ]
  
      operations = [
          migrations.AddField(
              model_name='machine',
              name='first_checkin',
              field=models.DateTimeField(auto_now_add=True, null=True),
          ),
          migrations.AddField(
              model_name='machine',
              name='sal_version',
              field=models.TextField(null=True, blank=True),
          ),
          migrations.RunPython(add_initial_date),
      ]
  
subject: Add in the first checkin date if it doesn't exist