code: def _make_ta_service_dict(self):
          
          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
docs: 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.