public function getTaxTotal()
    {
        $total = $this->UnitTax * $this->Quantity;

        $this->extend("updateTaxTotal", $total);

        return $total;
    }
public function getTaxTotal()
    {
        $total = $this->UnitTax * $this->Quantity;

        $this->extend("updateTaxTotal", $total);

        return $total;
    }
public function getTaxTotal ( ) { $ total = $ this -> UnitTax * $ this -> Quantity ; $ this -> extend ( "updateTaxTotal" , $ total ) ; return $ total ; }
Get the total amount of tax for a single unit of this item

@return float
Get the total amount of tax for a single unit of this item