public function testSetField()
{
$doc = new Document();
$doc->_id = 4;
$doc->name = 'Four';
$doc->content = 'Lorem ipsum four';
$expected = array('_id' => 4, 'name' => 'Four', 'content' => 'Lorem ipsum four');
$result = $doc->data();
$this->assertEqual($expected, $result);
}