public function testGet()
{
$structure = new Structure();
$structure->set('a.b.c.d', 'value');
// get unexisted
$this->assertEquals(null, $structure->get('unexisted-key'));
// get existed
$this->assertEquals('value', $structure->get('a.b.c.d'));
$this->assertEquals(array('d' => 'value'), $structure->get('a.b.c'));
$this->assertEquals(array('c' => array('d' => 'value')), $structure->get('a.b'));
$this->assertEquals(array('b' => array('c' => array('d' => 'value'))), $structure->get('a'));
}