code: def test_infer_from_tdi(self):
      # GH#23539
      # fast-path for inferring a frequency if the passed data already
      #  has one
      tdi = timedelta_range("1 second", periods=10**7, freq="1s")
  
      result = TimedeltaIndex(tdi, freq="infer")
      assert result.freq == tdi.freq
  
      # check that inferred_freq was not called by checking that the
      #  value has not been cached
      assert "inferred_freq" not in getattr(result, "_cache", {})
  
imports: from datetime import timedelta
  import numpy
  import pytest
  import pandas
  from pandas import Timedelta, TimedeltaIndex, timedelta_range, to_timedelta
  import pandas._testing
  from pandas.core.arrays.timedeltas import TimedeltaArray
label_desc: Use image node_id 5 for calling the TestTimedeltaIndex obj's underlying member method code with example usage: obj.test_infer_from_tdi() without return types