/**
* @depends testInitialState
* @return null
*/
public function testAddMetaTag()
{
$tag1 = $this->factory->createMetaTag('author', 'robert');
$this->assertEquals(array(), $this->head->getMetaTags());
$this->assertSame($this->head, $this->head->addMetaTag($tag1));
$expected = array($tag1);
$this->assertEquals($expected, $this->head->getMetaTags());
$tag2 = $this->factory->createMetaTag(null, null, null, 'UTF-8');
$this->assertSame($this->head, $this->head->addMetaTag($tag2));
$expected = array($tag1, $tag2);
$this->assertEquals($expected, $this->head->getMetaTags());
$tag3 = $this->factory->createMetaTag(null, 'text/html', 'Content-Type', 'UTF-8');
$this->assertSame($this->head, $this->head->addMetaTag($tag3));
$expected = array($tag1, $tag2, $tag3);
$this->assertEquals($expected, $this->head->getMetaTags());
}