public function setKeepAlive($keepAlive = true)
{
$this->keepAlive = $keepAlive;
$this->header['Connection'] = $keepAlive ? 'keep-alive' : 'close';
if ($keepAlive) {
$this->header['Keep-Ailve'] = $this->keepAliveTimeout;
} else {
unset($this->header['Keep-Ailve']);
}
}