code: func (con EtcdConnection) CheckEtcdServers() (done bool, err error) {
  	// Attempt to reach every Etcd server randomly.
  	serverNumber := len(con.ServerList)
  	serverPerms := rand.Perm(serverNumber)
  	for _, index := range serverPerms {
  		host, err := parseServerURI(con.ServerList[index])
  		if err != nil {
  			return false, err
  		}
  		if con.serverReachable(host) {
  			return true, nil
  		}
  	}
  	return false, nil
  }
docs: // CheckEtcdServers will attempt to reach all etcd servers once. If any
  // can be reached, return true.