Build our service and limits dict. This is laid out identical to
        ``self.all_services``, but keys limits by their ``ta_service_name``
        and ``ta_limit_name`` properties.

        :return: dict of TA service names to TA limit names to AwsLimit objects.

def _make_ta_service_dict(self):
        """
        Build our service and limits dict. This is laid out identical to
        ``self.all_services``, but keys limits by their ``ta_service_name``
        and ``ta_limit_name`` properties.

        :return: dict of TA service names to TA limit names to AwsLimit objects.
        """
        res = {}
        for svc_name in self.all_services:
            svc_obj = self.all_services[svc_name]
            for lim_name, lim in svc_obj.get_limits().items():
                if lim.ta_service_name not in res:
                    res[lim.ta_service_name] = {}
                res[lim.ta_service_name][lim.ta_limit_name] = lim
        return res