'Unsubscribe self.handlers from signals.'

def unsubscribe(self):

    for (signum, handler) in self._previous_handlers.items():
        signame = self.signals[signum]
        if (handler is None):
            self.bus.log(('Restoring    %s    handler    to    SIG_DFL.' % signame))
            handler = _signal.SIG_DFL
        else:
            self.bus.log(('Restoring    %s    handler    %r.' % (signame, handler)))
        try:
            our_handler = _signal.signal(signum, handler)
            if (our_handler is None):
                self.bus.log(('Restored    old    %s    handler    %r,    but    our    handler    was    not    registered.' % (signame, handler)), level=30)
        except ValueError:
            self.bus.log(('Unable    to    restore    %s    handler    %r.' % (signame, handler)), level=40, traceback=True)
