code: def get_encoded_filename(self, filename_parm):
          
          encoded_filename = force_text(filename_parm['filename*'])
          try:
              charset, lang, filename = encoded_filename.split('\'', 2)
              filename = urlparse.unquote(filename)
          except (ValueError, LookupError):
              filename = force_text(filename_parm['filename'])
          return filename
docs: Handle encoded filenames per RFC6266. See also:
          http://tools.ietf.org/html/rfc2231#section-4