code: def test_dataframe_to_csv():
      """Test to_csv with dataframe input
      - make certain the filename is deterministic
      - make certain the file contents match the data
      """
      data = _create_dataframe(10)
      try:
          result1 = pipe(data, to_csv)
          result2 = pipe(data, to_csv)
          filename = result1["url"]
          output = pd.read_csv(filename)
      finally:
          os.remove(filename)
  
      assert result1 == result2
      assert output.equals(data)
  
file_path: altair/tests/utils/test_data.py
imports: import os
  import pytest
  import pandas
  from toolz import pipe
  from altair.utils.data import limit_rows, MaxRowsError, sample, to_values, to_json, to_csv
label_desc: Use image node_id 9 for calling a global function with example usage: test_dataframe_to_csv() without return types