public function testCountClassmates()
{
$john = new DBStudent();
$john->setName('john');
$jean = new DBStudent();
$jean->setName('jean');
$phil = new DBStudent();
$phil->setName('phil');
$this->assertEquals(0, $john->countClassmates());
$john->setClassmates(array($jean, $phil));
$john->save();
$this->assertEquals(2, $john->countClassmates());
$john->removeClassmates();
$this->assertEquals(0, $john->countClassmates());
$john->save();
$this->assertEquals(0, $john->countClassmates());
$john->addClassmate($phil);
$this->assertEquals(1, $john->countClassmates());
$john->save();
$this->assertEquals(1, $john->countClassmates());
}
