def METHOD_NAME(self, request, *args, **kwargs):
    original = services.registration_fields(request, registration=self.get_object())
    required_keys = set(original.keys()) - set(request.data.keys())
    if len(required_keys) > 0:
        raise ValidationError(
            f"Missing keys '{', '.join(required_keys)}' in request",
            status.HTTP_400_BAD_REQUEST,
        )
    services.update_registration(
        registration=self.get_object(), field_values=request.data.items()
    )
    return Response(
        data=services.registration_fields(request, registration=self.get_object()),
        status=status.HTTP_200_OK,
    )