private function doClient($opt)
{
if (isset($_SESSION['sina']['access_token'])) {
$access_token = $_SESSION['sina']['access_token']['oauth_token'];
$refresh_token = $_SESSION['sina']['access_token']['oauth_token_secret'];
} else {
$access_token = $opt['oauth_token'];
$refresh_token = $opt['oauth_token_secret'];
}
return new SaeTClientV2($this->_sina_akey, $this->_sina_skey, $access_token, $refresh_token);
}