def connectionLost(self, reason):
        """
        Clean up when the connection has been lost.

        @type reason: L{Failure}
        @param reason: The reason the connection was terminated.
        """
        if self._onLogout is not None:
            self._onLogout()
            self._onLogout = None
        self.setTimeout(None)

        Clean up when the connection has been lost.

        @type reason: L{Failure}
        @param reason: The reason the connection was terminated.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/pop3.py