code: def test_get_loc_key_unit_mismatch_not_castable(self):
      dta = date_range("2000-01-01", periods=3)._data.astype("M8[s]")
      dti = DatetimeIndex(dta)
      key = dta[0].as_unit("ns") + pd.Timedelta(1)
  
      with pytest.raises(
          KeyError,
          match=r"Timestamp\('2000-01-01 00:00:00.000000001'\)",
      ):
          dti.get_loc(key)
  
      assert key not in dti
  
imports: from datetime import date, datetime, time, timedelta
  import numpy
  import pytest
  from pandas._libs import index
  from pandas.compat.numpy import np_long
  import pandas
  from pandas import DatetimeIndex, Index, Timestamp, bdate_range, date_range, notna
  import pandas._testing
  from pandas.tseries.frequencies import to_offset
label_desc: Use image node_id 2 for calling the TestGetLoc obj's underlying member method code with example usage: obj.test_get_loc_key_unit_mismatch_not_castable() without return types