gserviceaccount/opts.go
func Proxy(proxy string) Option {
	return func(gsa *GServiceAccount) error {
		u, err := url.Parse(proxy)
		if err != nil {
			return err
		}
		return Transport(&http.Transport{
			Proxy: http.ProxyURL(u),
		})(gsa)
	}
}
func Proxy(proxy string) Option {
	return func(gsa *GServiceAccount) error {
		u, err := url.Parse(proxy)
		if err != nil {
			return err
		}
		return Transport(&http.Transport{
			Proxy: http.ProxyURL(u),
		})(gsa)
	}
}
// Proxy is a GServiceAccount option to set a HTTP proxy used for by the token
// source.