class_docstr: Casting to and from ExtensionDtypes
code: def test_astype_object_series(self, all_data):
      ser = pd.Series(all_data, name="A")
      result = ser.astype(object)
      assert result.dtype == np.dtype(object)
      if hasattr(result._mgr, "blocks"):
          blk = result._mgr.blocks[0]
          assert isinstance(blk, NumpyBlock)
          assert blk.is_object
      assert isinstance(result._mgr.array, np.ndarray)
      assert result._mgr.array.dtype == np.dtype(object)
  
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 1 for calling the BaseCastingTests obj's underlying member method code with example usage: obj.test_astype_object_series(all_data) without return types