public function testItemManipulation()
 {
     $sUT = new Property();
     $sUT->addItem('test', new Item());
     $this->assertSame(1, count($sUT->getItems()));
     $sUT->addItem('test', new Item());
     $this->assertSame(1, count($sUT->getItems()));
     $this->setExpectedException('JSONSchema\\Structure\\Exceptions\\OverwriteKeyException');
     $sUT->addItem('test', new Item(), false, false);
 }