def getPublicKey(self):
        """
        Return a L{Key} from the first blob in C{self.blobs}, if any, or
        return L{None}.
        """
        if self.blobs:
            return keys.Key.fromString(self.blobs.pop(0))
        return None

        Return a L{Key} from the first blob in C{self.blobs}, if any, or
        return L{None}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/client/agent.py