code: def parse_authorization_header(authorization_header):
      
      auth_scheme = 'OAuth '.lower()
      if authorization_header[:len(auth_scheme)].lower().startswith(auth_scheme):
          items = parse_http_list(authorization_header[len(auth_scheme):])
          try:
              return list(parse_keqv_list(items).items())
          except (IndexError, ValueError):
              pass
      raise ValueError('Malformed authorization header')
docs: Parse an OAuth authorization header into a list of 2-tuples