public function testGetAncestor()
 {
     $ancestor = $this->dateProperty->getAncestor(0);
     $this->assertNotNull($ancestor);
     $this->assertInstanceOf('PHPCR\\NodeInterface', $ancestor);
     $this->assertTrue($this->rootNode->isSame($ancestor));
     $ancestor = $this->dateProperty->getAncestor(1);
     $this->assertNotNull($ancestor);
     $this->assertInstanceOf('PHPCR\\NodeInterface', $ancestor);
     $this->assertTrue($this->node->isSame($ancestor));
     //self
     $ancestor = $this->dateProperty->getAncestor($this->dateProperty->getDepth());
     $this->assertNotNull($ancestor);
     $this->assertInstanceOf('PHPCR\\PropertyInterface', $ancestor);
     $this->assertTrue($this->dateProperty->isSame($ancestor));
 }