* Fills given customer instance with all available data
* <p>
* @param customer Initial Customer instance
+ * <p>
* @return Prepared Customer instance
*/
public Customer fillCustomerData (final Customer customer);
* Checks if the the given customer instance is already registered
* <p>
* @param customer Customer instance
+ * <p>
* @return Whether the customer is already registered
*/
public boolean isReqistered (final Customer customer);
* persisting.
* <p>
* @param customer Initial customer instance
+ * <p>
* @return Prepared Customer instance
+ * <p>
* @throws
* org.mxchange.jshopcore.exceptions.CustomerAlreadyRegisteredException If
* the customer is already registered.