private function failswitch()
{
$n = count($this->uriList);
if ($n > 1) {
$i = $this->index + 1;
if ($i >= $n) {
$i = 0;
$this->failround++;
}
$this->index = $i;
$this->setUri($this->uriList[$i]);
} else {
$this->failround++;
}
$onFailswitch = $this->onFailswitch;
if (is_callable($onFailswitch)) {
call_user_func($onFailswitch, $this);
}
}