public function testFieldsExtraction()
{
$data = $this->extract($this->collection, array('id' => '[id]', 'name' => '[name]'));
$this->assertSame(array(array('id' => 1, 'name' => 'john'), array('id' => 2, 'name' => 'john 2'), array('id' => 3, 'name' => 'john 3')), $data);
}