package org.apidesign.apifest08.currency;

 /**

  * Convertor is an interface reprezenting a convertor between currencies.

  * It's able to convert one currency to the second one and back from the second one

  * to the primary.

  */

 public interface Convertor {

     /**

      * Convert amount of primary currency into secondary currency

      *

      * @param amount the amount in the primary currency

      * @return an amount in the secondary currency

      */

     Amount convert(Amount primaryAmount);

     /**

      * Convert amount of secondary currency back into primary currency

      *

      * @param amount the amount in the secondary currency

      * @return an amount in the primary currency

      */

     Amount convertBack(Amount secondaryAmount);

 }