@staticmethod
    def sign_sha256(key, msg):
        if isinstance(msg, text_type):
            msg = msg.encode('utf-8')
        return hmac.new(key, msg, hashlib.sha256).digest()
Generate an SHA256 HMAC, encoding msg to UTF-8 if not
dataset/ETHPy150Open sam-washington/requests-aws4auth/requests_aws4auth/aws4signingkey.py/AWS4SigningKey.sign_sha256