getTax() public method

The tax percentage on the shipping amount.
public getTax ( ) : Tax
return Tax
 /**
  * @depends testSerializationDeserialization
  * @param ShippingCost $obj
  */
 public function testGetters($obj)
 {
     $this->assertEquals($obj->getAmount(), CurrencyTest::getObject());
     $this->assertEquals($obj->getTax(), TaxTest::getObject());
 }