'Construct the login URL to start third party authentication.'

def _third_party_login_url(self, backend_name, auth_entry, login_params):

    return u'{url}?auth_entry={auth_entry}&{param_str}'.format(url=reverse('social:begin', kwargs={'backend': backend_name}), auth_entry=auth_entry, param_str=self._finish_auth_url_param(login_params))
