public function ubahKelas(Kelas $kelas)
{
$nama = $kelas->getNama();
$idKelas = $kelas->getIdKelas();
$ps = $this->connection->prepare("UPDATE SET nama=:nama where id_kelas=:idKelas ");
$ps->bindParam(":nama", $nama, PARAM_STR, 10);
$ps->bindParam("idKelas", $idKelas, PARAM_INT);
$ps->execute();
$this->connection = null;
}