content: from django.db import migrations, models
  import django.db.models.deletion
  import taggit.managers
  import utilities.fields
  import utilities.json
  import utilities.ordering
  import utilities.query_functions
  import utilities.tracking
  
  
  class Migration(migrations.Migration):
      dependencies = [
          ('extras', '0099_cachedvalue_ordering'),
          ('virtualization', '0037_protect_child_interfaces'),
      ]
  
      operations = [
          migrations.AddField(
              model_name='virtualmachine',
              name='virtual_disk_count',
              field=utilities.fields.CounterCacheField(
                  default=0, editable=False, to_field='virtual_machine', to_model='virtualization.VirtualDisk'
              ),
          ),
          migrations.CreateModel(
              name='VirtualDisk',
              fields=[
                  ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False)),
                  ('created', models.DateTimeField(auto_now_add=True, null=True)),
                  ('last_updated', models.DateTimeField(auto_now=True, null=True)),
                  (
                      'custom_field_data',
                      models.JSONField(blank=True, default=dict, encoder=utilities.json.CustomFieldJSONEncoder),
                  ),
                  ('name', models.CharField(max_length=64)),
                  (
                      '_name',
                      utilities.fields.NaturalOrderingField(
                          'name', blank=True, max_length=100, naturalize_function=utilities.ordering.naturalize_interface
                      ),
                  ),
                  ('description', models.CharField(blank=True, max_length=200)),
                  ('size', models.PositiveIntegerField()),
                  ('tags', taggit.managers.TaggableManager(through='extras.TaggedItem', to='extras.Tag')),
                  (
                      'virtual_machine',
                      models.ForeignKey(
                          on_delete=django.db.models.deletion.CASCADE,
                          related_name='%(class)ss',
                          to='virtualization.virtualmachine',
                      ),
                  ),
              ],
              options={
                  'verbose_name': 'virtual disk',
                  'verbose_name_plural': 'virtual disks',
                  'ordering': ('virtual_machine', utilities.query_functions.CollateAsChar('_name')),
                  'abstract': False,
              },
              bases=(models.Model, utilities.tracking.TrackingModelMixin),
          ),
          migrations.AddConstraint(
              model_name='virtualdisk',
              constraint=models.UniqueConstraint(
                  fields=('virtual_machine', 'name'), name='virtualization_virtualdisk_unique_virtual_machine_name'
              ),
          ),
      ]
  