old_contents: import os
  
  import graphviz
  
  
  def test_save_source_from_files(tmp_path):
      dot = graphviz.Digraph()
      dot.edge('hello', 'world')
      dot.render()
      old_stat = os.stat(dot.filepath)
  
      source = graphviz.Source.from_file(dot.filepath)
      source.save()
  
      assert os.stat(dot.filepath).st_mtime == old_stat.st_mtime
  
new_contents: import os
  
  import graphviz
  
  
  def test_save_source_from_files(tmp_path):
      dot = graphviz.Digraph(directory=tmp_path)
      dot.edge('hello', 'world')
      dot.render()
      old_stat = os.stat(dot.filepath)
  
      source = graphviz.Source.from_file(dot.filepath)
      source.save()
  
      assert os.stat(dot.filepath).st_mtime == old_stat.st_mtime
  
subject: move rest result for good