func (cs *clientset) Set(name string, c *http.Client) {
	if name == "" {
		cs.defaultClient = c
		return
	}
	cs.namedClients[name] = c
}
Set implements Clientset interface
package roundtrip
import (
	"bytes"
	"fmt"
	"io"
	"net/http"
	"github.com/caicloud/aloe/runtime"
)
type Clientset interface {
	DoRequest(rt *runtime.RoundTrip) (*http.Response, error)
	Set(name string, c *http.Client)
	Get(name string) (*http.Client, bool)
}
type clientset struct {
	defaultClient *http.Client
	namedClients  map[string]*http.Client
}
func NewClientset(c *http.Client) Clientset {
	cs := &clientset{
		defaultClient: c,
		namedClients:  map[string]*http.Client{},
	}
	if cs.defaultClient == nil {
		cs.defaultClient = http.DefaultClient
	}
	return cs
}