code: def test_prevent_casting(self, simple_index):
      index = simple_index
      result = index.astype("O")
      assert result.dtype == np.object_
  
imports: import numpy
  import pytest
  from pandas.core.dtypes.common import ensure_platform_int
  import pandas
  from pandas import Index, RangeIndex
  import pandas._testing
label_desc: Use image node_id 28 for calling the TestRangeIndex obj's underlying member method code with example usage: obj.test_prevent_casting(simple_index) without return types