class_docstr: Casting to and from ExtensionDtypes
code: def test_astype_str(self, data):
      result = pd.Series(data[:5]).astype(str)
      expected = pd.Series([str(x) for x in data[:5]], dtype=str)
      tm.assert_series_equal(result, expected)
  
file_path: pandas/pandas/tests/extension/base/casting.py
imports: import numpy
  import pytest
  import pandas.util._test_decorators
  import pandas
  import pandas._testing
  from pandas.core.internals.blocks import NumpyBlock
label_desc: Use image node_id 4 for calling the BaseCastingTests obj's underlying member method code with example usage: obj.test_astype_str(data) without return types