func GetAvailableProxyList() []*crawler.Proxy {
	return defaultCrawler.GetAvailableProxyList()
}
GetAvailableProxyList get available proxy lsit
package service
import (
	"errors"
	"time"
	"github.com/vicanso/proxy-pool/config"
	"github.com/vicanso/proxy-pool/crawler"
)
var (
	defaultCrawler = new(crawler.Crawler)
)
func init() {
	crawlerProxyList := make([]crawler.ProxyCrawler, 0)
	for _, item := range config.GetCrawlers() {
		interval := item.Interval
		var c crawler.ProxyCrawler
		switch item.Name {
		case crawler.ProxyIP66:
			ip66 := crawler.NewIP66Proxy(interval)
			ip66.LimitMaxPage(item.MaxPage)
			c = ip66
		case crawler.ProxyKuai:
			kuai := crawler.NewKuaiProxy(interval)
			kuai.LimitMaxPage(item.MaxPage)
			c = kuai
		default:
			xici := crawler.NewXiciProxy(interval)
			xici.LimitMaxPage(item.MaxPage)
			c = xici
		}
		crawlerProxyList = append(crawlerProxyList, c)
	}
	if len(crawlerProxyList) == 0 {
		panic(errors.New("no proxy crawler"))
	}
	defaultCrawler.Start(crawlerProxyList...)
	go func() {
		detectConfig := config.GetDetect()
		for range time.NewTicker(detectConfig.Interval).C {
			defaultCrawler.RedetectAvailableProxy()
		}
	}()
}