/**
  * Returns the tax rate for this fee.
  * 
  * @return int
  *
  * @author Sebastian Diel <*****@*****.**>
  * @since 16.11.2013
  */
 public function getTaxRate()
 {
     $taxRate = SilvercartShoppingCart::get_most_valuable_tax_rate();
     if ($taxRate === false) {
         $taxRate = $this->SilvercartTax()->getTaxRate();
     }
     return $taxRate;
 }