Lookup user data based on either his cloudflare_email or his
        unique_id.

        :param    cloudflare_email: email associated with user
        :type     cloudflare_email: str
        :param    unique_id:        unique id associated with user
        :type     unique_id:        str

        :returns:
        :rtype:   dict

def user_lookup(self, cloudflare_email=None, unique_id=None):
        """
        Lookup user data based on either his cloudflare_email or his
        unique_id.

        :param    cloudflare_email: email associated with user
        :type     cloudflare_email: str
        :param    unique_id:        unique id associated with user
        :type     unique_id:        str

        :returns:
        :rtype:   dict
        """
        if not cloudflare_email and not unique_id:
            raise KeyError(
                'Either cloudflare_email or unique_id must be present')

        params = {'act': 'user_lookup'}
        if cloudflare_email:
            params['cloudflare_email'] = cloudflare_email
        else:
            params['unique_id'] = unique_id

        return self._request(params)