public function test_accessors()
 {
     /** === Test Data === */
     $DISCOUNT = 'discount';
     $SALE_ITEM_ID = 'sale item id';
     $SUBTOTAL = 'subtotal';
     $TOTAL = 'total';
     /** === Call and asserts  === */
     $this->obj->setDiscount($DISCOUNT);
     $this->obj->setSaleItemId($SALE_ITEM_ID);
     $this->obj->setSubtotal($SUBTOTAL);
     $this->obj->setTotal($TOTAL);
     $this->assertEquals($DISCOUNT, $this->obj->getDiscount());
     $this->assertEquals($SALE_ITEM_ID, $this->obj->getSaleItemId());
     $this->assertEquals($SUBTOTAL, $this->obj->getSubtotal());
     $this->assertEquals($TOTAL, $this->obj->getTotal());
 }