def download_audit_trail(self, signature_id, document_id):
        """
        Get the audit trail of concrete document
        @signature_id: Id of signature
        @document_id: Id of document
        """
        connection = Connection(self.token)
        connection.set_url(self.production, self.SIGNS_DOCUMENTS_AUDIT_URL % (signature_id, document_id))

        response, headers = connection.file_request()

        if headers['content-type'] == 'application/json':
            return response

        return response
Get the audit trail of concrete document
        @signature_id: Id of signature
        @document_id: Id of document