code: def download_to_tempfile(url, file_name=None, extension=None):
      
  
      if not file_name:
          file_name = generate_timestamped_string("wtf_temp_file")
  
      if extension:
          file_path = temp_path(file_name + extension)
      else:
          ext = ""
          try:
              ext = re.search(u"\\.\\w+$", file_name).group(0)
          except:
              pass
          file_path = temp_path(file_name + ext)
  
      webFile = urllib.urlopen(url)
      localFile = open(file_path, 'w')
      localFile.write(webFile.read())
      webFile.close()
      localFile.close()
  
      return file_path
docs: Downloads a URL contents to a tempfile.  This is useful for testing downloads.
      It will download the contents of a URL to a tempfile, which you then can 
      open and use to validate the downloaded contents.
  
      Args:
          url (str) : URL of the contents to download.
  
      Kwargs:
          file_name (str): Name of file.
          extension (str): Extension to use.
  
      Return:
          str - Returns path to the temp file.