telnet.py 文件源码

def do(option):
        """Indicate a desire for the peer to begin performing the given option.

        Returns a Deferred that fires with True when the peer begins performing
        the option, or False when the peer refuses to perform it.  If the peer
        is already performing the given option, the Deferred will fail with
        L{AlreadyEnabled}.  If a negotiation regarding this option is already
        in progress, the Deferred will fail with L{AlreadyNegotiating}.

        Note: It is currently possible that this Deferred will never fire,
        if the peer never responds, or if the peer believes the option to
        already be enabled.
        """