'Handle DONT commands according to RF1143'

def _handle_dont(self, opt):

    if (self.us[opt] == NO):
        pass
    elif (self.us[opt] == YES):
        if self._can_we_disable(opt):
            self.us[opt] = NO
            self.send_wont(opt)
            self._notify_us(opt, False)
        else:
            self.send_will(opt)
    elif (self.us[opt] == WANTNO):
        if (self.usq[opt] == EMPTY):
            self.us[opt] = NO
        elif (self.usq[opt] == OPPOSITE):
            self.us[opt] = WANTYES
            self.usq[opt] = EMPTY
            self.send_will(opt)
    elif (self.us[opt] == WANTYES):
        if (self.usq[opt] == EMPTY):
            self.us[opt] = NO
        elif (self.usq[opt] == OPPOSITE):
            self.us[opt] = NO
            self.usq[opt] = EMPTY
