func (c *client) MaybeRenderTo(url, callback string) string {
	return renderTo(callback, url)
}
maybe open other to login steam
package steam
import (
	"net/url"
)
type (
	Client interface {
		SetReq(req Req)
		RenderTo(callback string) string
		MaybeRenderTo(url, callback string) string
		OpenidBindQuery(param url.Values) (res *openidRes, err error)
		OpenidBindMap(param map[string]string) (res *openidRes, err error)
		Api() Api
	}
	client struct {
		appKey string
		req    Req
	}
)
func NewClient(appKey string) Client {
	return &client{
		appKey: appKey,
		req:    NewDefReq(),
	}
}
func (c *client) SetReq(req Req) {
	c.req = req
}
func (c *client) RenderTo(callback string) string {
	return renderTo(callback)
}