new_contents: # -*- coding: utf-8 -*-
  from __future__ import unicode_literals
  
  from django.db import models, migrations
  
  
  def clear_old_scenario_results(apps, schema_editor):
      Scenario = apps.get_model('modeling', 'Scenario')
      old_scenarios = Scenario.objects.filter(
              project__model_package='tr-55'
          )
  
      for scenario in old_scenarios:
          scenario.results = '[]'
          scenario.modification_hash = ''
          scenario.save()
  
  
  class Migration(migrations.Migration):
  
      dependencies = [
          ('modeling', '0020_old_scenarios'),
      ]
  
      operations = [
          migrations.RunPython(clear_old_scenario_results)
      ]
  
subject: Add migration to flush saved tr-55 results