def create_session(self, **params):
        """
        Create the session
        date format: YYYY-MM-DDThh:mm
        location: ISO code
        """

        required_keys = ('market', 'currency', 'locale', 'pickupplace',
                         'dropoffplace', 'pickupdatetime', 'dropoffdatetime',
                         'driverage')

        service_url = "{url}/{params_path}".format(
            url=self.PRICING_SESSION_URL,
            params_path=self._construct_params(params, required_keys)
        )

        poll_path = self.make_request(service_url,
                                      headers=self._session_headers(),
                                      callback=lambda resp: resp.headers[
                                          'location'],
                                      userip=params['userip'])

        return "{url}{path}".format(url=self.API_HOST, path=poll_path)