protected function addHttpMock(Net_WebFinger $wf)
 {
     $this->adapter = new HTTP_Request2_Adapter_LogMock();
     $req = new HTTP_Request2();
     $req->setAdapter($this->adapter);
     $wf->setHttpClient($req);
     return $this;
 }
<?php

require_once 'HTTP/Request2.php';
require_once 'Net/WebFinger.php';
$req = new HTTP_Request2();
$req->setConfig('follow_redirects', true);
$req->setHeader('User-Agent', 'Net_WebFinger custom-http-adapter example');
$wf = new Net_WebFinger();
$wf->setHttpClient($req);
$react = $wf->finger('*****@*****.**');
foreach ($react as $link) {
    echo 'Link: ' . $link->rel . ': ' . ($link->href ? $link->href : $link->template) . "\n";
}
echo "..done\n";