'Persist the error with this into FileUpload (but do not persist
the file contents, which are too large) and return a ValidationError.'

def persist_errors(self, errors, upload):

    validation = {'errors': len(errors), 'success': False, 'messages': errors}
    self.file_upload = FileUpload.objects.create(user=self.user, name=getattr(upload, 'name', ''), validation=json.dumps(validation))
    return forms.ValidationError('    '.join((e['message'] for e in errors)))
