old_contents: from rest_framework.decorators import api_view
  from rest_framework.response import Response
  from rest_framework.exceptions import NotFound
  
  from kobo.apps.subsequences.models import MockSubmission
  
  from kpi.models import Asset
  
  
  @api_view(['POST', 'PATCH', 'GET'])
  def advanced_submission_post(request):
      posted_data = request.data
      submission_uuid = request.data['submission_uuid']
      asset_uid = request.data['asset_uid']
      asset = Asset.objects.get(uid=asset_uid)
      try:
          submission = asset.submissions.get(uuid=submission_uuid)
          submission.patch_content(request.data)
      except MockSubmission.DoesNotExist:
          raise NotFound('submission not found')
      # what does the front end want back?
      return Response({})
  
new_contents: from rest_framework.decorators import api_view
  from rest_framework.response import Response
  # from rest_framework.exceptions import NotFound
  
  from kobo.apps.subsequences.models import MockSubmission
  
  from kpi.models import Asset
  
  
  @api_view(['POST', 'PATCH', 'GET'])
  def advanced_submission_post(request):
      posted_data = request.data
      submission_uuid = request.data['submission_uuid']
      asset_uid = request.data['asset_uid']
      asset = Asset.objects.get(uid=asset_uid)
      try:
          submission = asset.submissions.get(uuid=submission_uuid)
      except MockSubmission.DoesNotExist:
          submission = asset.submissions.create(uuid=submission_uuid)
      submission.patch_content(request.data)
      # what does the front end want back?
      return Response(submission.content)
  
subject: create a MockSubmission when one is not found