public function testRebuildRecomputesDepth()
 {
     $this->assertTrue(Category::isValidNestedSet());
     Category::query()->update(array('lft' => null, 'rgt' => null, 'depth' => 0));
     $this->assertFalse(Category::isValidNestedSet());
     Category::rebuild();
     $expected = array(0, 1, 1, 2, 1, 0);
     $this->assertEquals($expected, Category::all()->map(function ($n) {
         return $n->getDepth();
     })->all());
 }