def addIdentity(self, blob, comment = b''):
        """
        Add a private key blob to the agent's collection of keys.
        """
        req = blob
        req += NS(comment)
        return self.sendRequest(AGENTC_ADD_IDENTITY, req)

        Add a private key blob to the agent's collection of keys.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/ssh/agent.py