$conf = $this->configIO->read($dest);
$conf['redirector'] = 'blabla';
$this->configIO->write($dest, $conf);
$conf = $this->configIO->read($dest);
$this->assertEquals('blabla', $conf['redirector']);
$conf = $this->configIO->read($dest);
$conf['redirector'] = 'blabla';
$this->configIO->write($dest, $conf);
$conf = $this->configIO->read($dest);
$this->assertEquals('blabla', $conf['redirector']);