code: def _add_delta_tdi(self, other):
          
          assert isinstance(self.freq, Tick)  # checked by calling function
  
          delta = self._check_timedeltalike_freq_compat(other)
          return self._addsub_int_array(delta, operator.add).asi8
docs: Parameters
          ----------
          other : TimedeltaArray or ndarray[timedelta64]
  
          Returns
          -------
          result : ndarray[int64]