code: def test_astype_raises(self, dtype):
      # GH 13149, GH 13209
      idx = TimedeltaIndex([1e14, "NaT", NaT, np.nan])
      msg = "Cannot cast TimedeltaIndex to dtype"
      with pytest.raises(TypeError, match=msg):
          idx.astype(dtype)
  
file_path: pandas/pandas/tests/indexes/timedeltas/methods/test_astype.py
imports: from datetime import timedelta
  import numpy
  import pytest
  import pandas
  from pandas import Index, NaT, Timedelta, TimedeltaIndex, timedelta_range
  import pandas._testing
  from pandas.core.arrays import TimedeltaArray
label_desc: Use image node_id 9 for calling the TestTimedeltaIndex obj's underlying member method code with example usage: obj.test_astype_raises(dtype) without return types