/**
  * @param $id
  *
  * @return AB_Customer
  */
 public function getCustomer($id)
 {
     $customer = new AB_Customer();
     $customer_data = $this->getWpdb()->get_row($this->getWpdb()->prepare('SELECT * FROM `ab_customer` WHERE id = %d', $id));
     // populate customer with data
     if ($customer_data) {
         $customer->setData($customer_data);
     }
     return $customer;
 }