code: def test_add_timedelta_preserves_freq(self):
      # GH#37295 should hold for any DTI with freq=None or Tick freq
      tz = "Canada/Eastern"
      dti = date_range(
          start=Timestamp("2019-03-26 00:00:00-0400", tz=tz),
          end=Timestamp("2020-10-17 00:00:00-0400", tz=tz),
          freq="D",
      )
      result = dti + Timedelta(days=1)
      assert result.freq == dti.freq
  
imports: import pytest
  from pandas import Timedelta, TimedeltaIndex, Timestamp, date_range, timedelta_range
  import pandas._testing
label_desc: Use image node_id 1 for calling the TestDatetimeIndexArithmetic obj's underlying member method code with example usage: obj.test_add_timedelta_preserves_freq() without return types