code: def test_append_preserve_index_name(self):
      # #980
      df1 = DataFrame(columns=["A", "B", "C"])
      df1 = df1.set_index(["A"])
      df2 = DataFrame(
          data=[[1, 4, 7], [2, 5, 8], [3, 6, 9]],
          columns=["A", "B", "C"],
      )
      df2 = df2.set_index(["A"])
  
      msg = "The behavior of array concatenation with empty entries is deprecated"
      with tm.assert_produces_warning(FutureWarning, match=msg):
          result = df1._append(df2)
      assert result.index.name == "A"
  
imports: import datetime
  from itertools import combinations
  import dateutil
  import numpy
  import pytest
  import pandas
  from pandas import DataFrame, Index, Series, Timestamp, concat, isna
  import pandas._testing
label_desc: Use image node_id 10 for calling the TestAppend obj's underlying member method code with example usage: obj.test_append_preserve_index_name() without return types