var DefaultRoundTripper http.RoundTripper = &http.Transport{
	Proxy: http.ProxyFromEnvironment,
	DialContext: (&net.Dialer{
		Timeout:   30 * time.Second,
		KeepAlive: 30 * time.Second,
	}).DialContext,
	TLSHandshakeTimeout: 10 * time.Second,
}

type Client interface {
	URL(ep string, args map[string]string) *url.URL
	Do(context.Context, *http.Request) (*http.Response, []byte, error)
}

type CloseIdler interface {
	CloseIdleConnections()
}

type Config struct {
	// The address of the Prometheus to connect to.
	Address string

	// Client is used by the Client to drive HTTP requests. If not provided,
	// a new one based on the provided RoundTripper (or DefaultRoundTripper) will be used.
	Client *http.Client

	// RoundTripper is used by the Client to drive HTTP requests. If not
	// provided, DefaultRoundTripper will be used.
	RoundTripper http.RoundTripper
}