public function testOutOfRangeCharacterOccurrence($string, $isValid)
{
if (false === $isValid) {
$this->setExpectedException('PHPCR\\ValueFormatException', 'Invalid character detected');
}
$root = $this->session->getNode('/');
$article = $root->addNode('article');
$article->setProperty('test', $string);
$this->session->save();
}