def change_tunnel_ad_url(self):
        ''' Change tunnel ad url. '''
        if self.is_open:
            self.close()
        req = requests.delete('https://api.psiturk.org/api/tunnel/',
                              auth=(self.access_key, self.secret_key))
        # the request content here actually will include the tunnel_hostname
        # if needed or wanted.
        if req.status_code in [401, 403, 500]:
            print(req.content)
            return False
Change tunnel ad url.