static function createRetention($input)
{
$retention = new Retention();
$retention->customer_id = $input['customer_id'];
$retention->student_id = $input['student_id'];
$retention->franchisee_id = Session::get('franchiseId');
$retention->created_at = date("Y-m-d H:i:s");
$retention->created_by = Session::get('userId');
$retention->save();
return $retention;
}
