@staticmethod
    def sign_sha256(key, msg):
        if isinstance(msg, text_type):
            msg = msg.encode('utf-8')
        return hmac.new(key, msg, hashlib.sha256).digest()
How existing transactions should be handled.
dataset/ETHPy150Open sam-washington/requests-aws4auth/requests_aws4auth/aws4signingkey.py/AWS4SigningKey.sign_sha256--crossover with--dataset/ETHPy150Open GoogleCloudPlatform/python-compat-runtime/appengine-compat/exported_appengine_sdk/google/appengine/datastore/datastore_rpc.py/TransactionOptions.propagation