class_docstr: Casting to and from ExtensionDtypes
code: def test_astype_empty_dataframe(self, dtype):
      # https://github.com/pandas-dev/pandas/issues/33113
      df = pd.DataFrame()
      result = df.astype(dtype)
      tm.assert_frame_equal(result, df)
  
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 7 for calling the BaseCastingTests obj's underlying member method code with example usage: obj.test_astype_empty_dataframe(dtype) without return types