class_docstr: Tests common to IntervalIndex with any subtype
class_docstr_tok: ["Tests","common","to","IntervalIndex","with","any","subtype"]
code: def test_astype_invalid_dtype(self, index):
      msg = "data type [\"']fake_dtype[\"'] not understood"
      with pytest.raises(TypeError, match=msg):
          index.astype("fake_dtype")
  
imports: import re
  import numpy
  import pytest
  from pandas.core.dtypes.dtypes import CategoricalDtype, IntervalDtype
  from pandas import CategoricalIndex, Index, IntervalIndex, NaT, Timedelta, Timestamp, interval_range
  import pandas._testing
label_desc: Use image node_id 5 for calling the AstypeTests obj's underlying member method code with example usage: obj.test_astype_invalid_dtype(index) without return types