code: def test_astype_empty_dtype_dict(self):
      # issue mentioned further down in the following issue's thread
      # https://github.com/pandas-dev/pandas/issues/33113
      df = DataFrame()
      result = df.astype({})
      tm.assert_frame_equal(result, df)
      assert result is not df
  
imports: import re
  import numpy
  import pytest
  import pandas.util._test_decorators
  import pandas
  from pandas import Categorical, CategoricalDtype, DataFrame, DatetimeTZDtype, Index, Interval, IntervalDtype, NaT, Series, Timedelta, Timestamp, concat, date_range, option_context
  import pandas._testing
label_desc: Use image node_id 32 for calling the TestAstype obj's underlying member method code with example usage: obj.test_astype_empty_dtype_dict() without return types