public function testGetTaxedPrice()
 {
     $taxes = [new TaxRate(20, 'PST', 't1'), new TaxRate(30, 'PST', 't2'), new TaxRate(40, 'PST', 't3')];
     $collection = new TaxRateCollection($taxes);
     $this->assertEquals(190, $collection->getTaxedPrice(100));
 }