code: def mime_type(self):
          
          guesses = None
          if self.path:
              guesses = guess_type(self.path)
          return guesses and guesses[0] or self.DEFAULT_MIME_TYPE
docs: :return: String describing the mime type of this file (based on the filename)
          :note: Defaults to 'text/plain' in case the actual file type is unknown.