in internal/http/request.go [116:129]
func cloneUrlValues(oldV url.Values) url.Values {
nv := 0
for _, vv := range oldV {
nv += len(vv)
}
sv := make([]string, nv)
newV := make(url.Values, len(oldV))
for k, vv := range oldV {
n := copy(sv, vv)
newV[k] = sv[:n:n]
sv = sv[n:]
}
return newV
}