code: def test_render_to_file(Chart, datas):
      """Test in file rendering"""
      file_name = "/tmp/test_graph-%s.svg" % uuid.uuid4()
      if os.path.exists(file_name):
          os.remove(file_name)
  
      chart = Chart()
      chart = make_data(chart, datas)
      chart.render_to_file(file_name)
      with io.open(file_name, encoding="utf-8") as f:
          assert "pygal" in f.read()
      os.remove(file_name)
  
imports: import io
  import os
  import uuid
  import pytest
  import pygal
  from pygal.graph.map import BaseMap
  from pygal.test import make_data
  from pygal.util import cut
label_desc: Use image node_id 2 for calling a global function with example usage: test_render_to_file(Chart, datas) without return types