code: def test_handle_empty_objects(self, sort, using_infer_string):
      df = DataFrame(
          np.random.default_rng(2).standard_normal((10, 4)),
          columns=list("abcd"),
      )
  
      dfcopy = df[:5].copy()
      dfcopy["foo"] = "bar"
      empty = df[5:5]
  
      frames = [dfcopy, empty, empty, df[5:]]
      concatted = concat(frames, axis=0, sort=sort)
  
      expected = df.reindex(columns=["a", "b", "c", "d", "foo"])
      expected["foo"] = expected["foo"].astype(
          object if not using_infer_string else "string[pyarrow_numpy]"
      )
      expected.loc[0:4, "foo"] = "bar"
  
      tm.assert_frame_equal(concatted, expected)
  
      # empty as first element with time series
      # GH3259
      df = DataFrame(
          {"A": range(10000)},
          index=date_range("20130101", periods=10000, freq="s"),
      )
      empty = DataFrame()
      result = concat([df, empty], axis=1)
      tm.assert_frame_equal(result, df)
      result = concat([empty, df], axis=1)
      tm.assert_frame_equal(result, df)
  
      result = concat([df, empty])
      tm.assert_frame_equal(result, df)
      result = concat([empty, df])
      tm.assert_frame_equal(result, df)
  
imports: import numpy
  import pytest
  import pandas
  from pandas import DataFrame, RangeIndex, Series, concat, date_range
  import pandas._testing
label_desc: Use image node_id 1 for calling the TestEmptyConcat obj's underlying member method code with example usage: obj.test_handle_empty_objects(sort, using_infer_string) without return types