protected function visit($value)
{
$this->getVisitorMock()->expects($this->once())->method('visitValueObject')->with($value->value);
$visitor = $this->getVisitor();
$generator = $this->getGenerator();
$generator->startDocument(null);
$visitor->visit($this->getVisitorMock(), $generator, $value);
return $generator->endDocument(null);
}