func (o OAuth) NewTokensFromRequest(req *http.Request) (*oauthTokens, error) {
	query := req.URL.Query()
	code := query.Get("code")
	return o.GetTokens(code, "authorization_code")
}
func (o OAuth) NewTokensFromRequest(req *http.Request) (*oauthTokens, error) {
	query := req.URL.Query()
	code := query.Get("code")
	return o.GetTokens(code, "authorization_code")
}
// NewTokensRequest generates new tokens for OAuth user given an http request
// containing the query parameter 'code'