According to http.Client and http.Transport documentation in Go's built-in net/http package:
// The Client's Transport typically has internal state (cached TCP
// connections), so Clients should be reused instead of created as
// needed. Clients are safe for concurrent use by multiple goroutines.
So I just wonder: is it safe for concurrent modification too or not? since I wanna perform 20K http.Request with single http.Client struct and different values concurrently, not consecutively.