ClaimsSupported                  []string `json:"claims_supported,omitempty"`
	CodeChallengeMethodsSupported    []string `json:"code_challenge_methods_supported,omitempty"`
}

func parseDiscoveryDoc(u *xnet.URL, transport http.RoundTripper, closeRespFn func(io.ReadCloser)) (DiscoveryDoc, error) {
	d := DiscoveryDoc{}
	req, err := http.NewRequest(http.MethodGet, u.String(), nil)
	if err != nil {
		return d, err