* <p>
* @param user User instance to get list of shared address books (shares)
* from
+ *
* @return List of shares (= shared address book entries)
*/
List<ShareableAddressbook> allSharedAddressbooks (final User user);
* <p>
* @param sharee User sharee instance
* @param addressbook Address book instance
+ *
* @return Updated share instance
+ *
* @throws
* org.mxchange.addressbook.exceptions.UserAlreadySharingAddressbookException
* When the user is already sharing the address book
* Checks if the given user is sharing address books with others
* <p>
* @param user User instance
+ *
* @return Whether the user is sharing address books
*/
Boolean isUserSharingAddressbooks (final User user);