code: def test_append(idx):
      result = idx[:3].append(idx[3:])
      assert result.equals(idx)
  
      foos = [idx[:1], idx[1:3], idx[3:]]
      result = foos[0].append(foos[1:])
      assert result.equals(idx)
  
      # empty
      result = idx.append([])
      assert result.equals(idx)
  
file_path: pandas/pandas/tests/indexes/multi/test_reshape.py
imports: from datetime import datetime
  import numpy
  import pytest
  import pytz
  import pandas
  from pandas import Index, MultiIndex
  import pandas._testing
label_desc: Use image node_id 3 for calling a global function with example usage: test_append(idx) without return types