Get all the relationships by key/val & return them

        A normalized relationship dict uses the key name without
        any alteration but the value will be the `id` provided
        in the payload if present. If not present, then the client
        wants to unset the relationship so it will be set to None.

        INFO: only works for to-one relationships.

        :param relationships:
            dict JSON API relationships object
        :return: dict

def _normalize_relationships(relationships):
        """ Get all the relationships by key/val & return them

        A normalized relationship dict uses the key name without
        any alteration but the value will be the `id` provided
        in the payload if present. If not present, then the client
        wants to unset the relationship so it will be set to None.

        INFO: only works for to-one relationships.

        :param relationships:
            dict JSON API relationships object
        :return: dict
        """

        ret = {}

        for key, val in relationships.items():
            if not val['data']:
                ret[key] = None
            else:
                ret[key] = val['data']['id']

        return ret