Provide custom `CheckRedirect` for `r2.Request.Client`. about go-sdk HOT 3 CLOSED

package main

import (
	"fmt"
	"net/http"
	"net/http/httptest"
	"net/url"

	"github.com/blend/go-sdk/r2"
)

func main() {
	path := "/v1/auth/token/lookup"
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path == path {
			http.Redirect(w, r, "/more", http.StatusTemporaryRedirect)
			return
		}
		fmt.Fprintln(w, "Hello, client")
	}))
	defer ts.Close()
	u, err := url.Parse(ts.URL)
	if err != nil {
		panic(err)
	}

	// Do a GET.
	fmt.Println("--- Doing a GET ---")
	opts := []r2.Option{
		r2.OptScheme("http"),
		r2.OptHeaderValue("X-Vault-Token", "bar"),
		r2.OptHost(u.Host),
		r2.OptGet(),
		r2.OptPathf(path),
	}
	body, res, err := r2.New("", opts...).Bytes()
	if err != nil {
		panic(err)
	}
	fmt.Printf("body: %q\n\n%#v\n", string(body), res)

	// Do a POST.
	fmt.Println("--- Doing a POST ---")
	opts = []r2.Option{
		r2.OptScheme("http"),
		r2.OptHeaderValue("X-Vault-Token", "bar"),
		r2.OptHost(u.Host),
		r2.OptPost(),
		r2.OptPathf(path),
		r2.OptJSONBody(map[string]string{"token": "foo"}),
	}
	body, res, err = r2.New("", opts...).Bytes()
	if err != nil {
		panic(err)
	}
	fmt.Printf("body: %q\n\n%#v\n", string(body), res)
}

package main

import (
	"fmt"
	"net/http"
	"net/http/httptest"
	"net/url"

	"github.com/blend/go-sdk/r2"
)

func main() {
	path := "/v1/auth/token/lookup"
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Redirect(w, r, path, http.StatusTemporaryRedirect)
	}))
	defer ts.Close()
	u, err := url.Parse(ts.URL)
	if err != nil {
		panic(err)
	}

	// Do a GET.
	fmt.Println("--- Doing a GET ---")
	opts := []r2.Option{
		r2.OptScheme("http"),
		r2.OptHeaderValue("X-Vault-Token", "bar"),
		r2.OptHost(u.Host),
		r2.OptGet(),
		r2.OptPathf(path),
	}
	_, _, err = r2.New("", opts...).Bytes()
	if err == nil {
		panic("SHOULD ERR")
	}
	unwrapped, ok := err.(*url.Error)
	if !ok {
		panic("SHOULD UNWRAP")
	}

	fmt.Printf("%#v\n", unwrapped)
	fmt.Printf("%#v\n", unwrapped.Err)
}