protected function createNodes()
{
$node = new Tag(array(), 'div', array());
$this->assertFalse($node->hasChilds());
$nodeB = new Tag(array(), 'div', array());
$node->addChild($nodeB);
$this->assertTrue($node->hasChilds());
$this->assertSame($node, $nodeB->getParent());
$nodeC = new Tag(array(), 'div', array());
$node->addChild($nodeC);
$this->assertSame(2, count($node->getChilds()));
$this->assertSame($node, $nodeC->getParent());
$this->assertSame(null, $nodeB->getPreviousSibling());
$this->assertSame($nodeC, $nodeB->getNextSibling());
$this->assertSame($nodeB, $nodeC->getPreviousSibling());
$this->assertSame(null, $nodeC->getNextSibling());
$nodeD = new Tag(array(), 'div', array());
$node->addChild($nodeD);
$this->assertSame($nodeB, $nodeC->getPreviousSibling());
$this->assertSame($nodeD, $nodeC->getNextSibling());
return compact('node', 'nodeB', 'nodeC', 'nodeD');
}
