code: def test_dump_csv_with_utf8(self):
      df = pd.DataFrame({"あ": [1, 2, 3], "い": [4, 5, 6]})
      processor = CsvFileProcessor()
  
      with tempfile.TemporaryDirectory() as temp_dir:
          temp_path = f"{temp_dir}/temp.csv"
  
          local_target = LocalTarget(
              path=temp_path, format=processor.format()
          )
          with local_target.open("w") as f:
              processor.dump(df, f)
  
          # read with utf-8 to check if the file is dumped with utf8
          loaded_df = pd.read_csv(temp_path, encoding="utf-8")
          pd.testing.assert_frame_equal(df, loaded_df)
  
file_path: gokart/test/test_file_processor.py
imports: import tempfile
  import unittest
  import pandas
  from luigi import LocalTarget
  from gokart.file_processor import CsvFileProcessor
label_desc: Use image node_id 1 for calling the TestCsvFileProcessor obj's underlying member method code with example usage: obj.test_dump_csv_with_utf8() without return types