def _signing_str(self):
        """
        Returns (str):
            A string used to sign the AWS Signature V4 payload in the format:
                <Algorithm>\n
                <Timestamp>\n
                <Scope>\n
                <CanonicalRequestHash>
        """
        canonical_request_hash = self.hashfunc(self._canonical_request.encode('utf-8')).hexdigest()
        return '\n'.join((self.algorithm, self.timestamp, self._scope, canonical_request_hash))

        Returns (str):
            A string used to sign the AWS Signature V4 payload in the format:
                <Algorithm>

                <Timestamp>

                <Scope>

                <CanonicalRequestHash>
        
kafka/sasl/msk.py