code: def get_or_create_shared_key(cls, force_new=False):
          
          if force_new:
              with transaction.atomic():
                  SharedKey.objects.filter(current=True).update(current=False)
                  key = Key()
                  return SharedKey.objects.create(public_key=key,
                                                  private_key=key,
                                                  current=True)
          # create a new shared key if one doesn't exist
          try:
              return SharedKey.objects.get(current=True)
          except SharedKey.DoesNotExist:
              key = Key()
              return SharedKey.objects.create(public_key=key,
                                              private_key=key,
                                              current=True)
docs: Create a shared public/private key pair for certificate pushing,
          if the settings allow.