验证activerecord

Question

请解释一下这段代码。 具体来说，数组中的元素：name，blah和bleh。我检查用户名和电子邮件的唯一性

class User extends ActiveRecord\Model
{
  static $validates_uniqueness_of = array(
    array('name'),
    array(array('blah','bleh'), 'message' => 'blah and bleh!')
  );
}

User::create(array('name' => 'Tito'));
$user = User::create(array('name' => 'Tito'));
$user->is_valid();