public function testEach() {
		$collection = new DocumentSet();
		$collection->set(array(
			'title' => 'Lorem Ipsum',
			'key'   => 'value',
			'foo'   => 'bar'
		));
		$collection->each(function($value) {
			return $value . ' test';
		});
		$expected = array(
			'Lorem Ipsum test',
			'value test',
			'bar test'
		);
		$this->assertEqual($collection->to('array'), $expected);
	}