public function testFieldAccess()
{
$m = new Model();
$m->addField('name');
$m->addField('surname');
$m['name'] = 5;
$this->assertEquals(5, $m->get('name'));
$m->set('surname', 'Bilbo');
$this->assertEquals(5, $m->get('name'));
$this->assertEquals('Bilbo', $m->get('surname'));
$this->assertEquals(['name' => 5, 'surname' => 'Bilbo'], $m->get());
}