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