code: def find_token_type(self, request):
          
          estimates = sorted(((t.estimate_type(request), n)
                              for n, t in self.tokens.items()), reverse=True)
          return estimates[0][1] if len(estimates) else None
docs: Token type identification.
  
          RFC 6749 does not provide a method for easily differentiating between
          different token types during protected resource access. We estimate
          the most likely token type (if any) by asking each known token type
          to give an estimation based on the request.