/**
  * @depends	testInterface
  * @return	null
  */
 public function testAddCssFile()
 {
     $this->assertEquals(array(), $this->htmlDoc->getLinkTags());
     $this->assertSame($this->htmlDoc, $this->htmlDoc->addCssFile('mycss.css'));
     $link1 = new Link('mycss.css');
     $this->assertEquals(array($link1), $this->htmlDoc->getLinkTags());
     $this->assertSame($this->htmlDoc, $this->htmlDoc->addCssFile('your.css', 'print'));
     $link2 = new Link('your.css', 'print');
     $expected = array($link1, $link2);
     $this->assertEquals($expected, $this->htmlDoc->getLinkTags());
     $this->assertSame($this->htmlDoc, $this->htmlDoc->addCssFile('our.css', 'screen', 'text/html'));
     $link3 = new Link('our.css', 'screen', 'text/html');
     $expected = array($link1, $link2, $link3);
     $this->assertEquals($expected, $this->htmlDoc->getLinkTags());
 }