public function testExpand()
{
$data = array('Gallery.Image' => null, 'Gallery.Image.Tag' => null, 'Gallery.Image.Tag.Author' => null);
$expected = array('Gallery' => array('Image' => array('Tag' => array('Author' => null))));
$this->assertEqual($expected, Set::expand($data));
$data = array('Gallery.Image.Tag' => null, 'Gallery.Image' => null, 'Gallery.Image.Tag.Author' => null);
$expected = array('Gallery' => array('Image' => array('Tag' => array('Author' => null))));
$this->assertEqual($expected, Set::expand($data));
$data = array('Gallery.Image.Tag.Author' => null, 'Gallery.Image.Tag' => null, 'Gallery.Image' => null);
$expected = array('Gallery' => array('Image' => array('Tag' => array('Author' => null))));
$this->assertEqual($expected, Set::expand($data));
}