/**
  * @dataProvider getPrevData
  */
 public function testGetPrev($expected, $path, $anchor = null, $depth = null, $class = 'Doctrine\\ODM\\PHPCR\\Document\\Generic')
 {
     $prev = $this->helper->getPrev($path, $anchor, $depth);
     if (null === $expected) {
         $this->assertNull($prev);
     } else {
         $this->assertInstanceOf($class, $prev);
         $this->assertEquals($expected, $prev->getId());
     }
 }