makes it possible to register listeners which are called whenever
an accessibility event (see ::drafts::com::sun::star::accessibility::AccessibleEventObject ) occurs.
The ::AccessibleExtendedComponent interface contains
additional methods to those of the ::AccessibleComponent
interface. These methods provide more seldom used information. The
division into two interfaces allows classes to support the more
frequently used methods of the ::AccessibleComponent
interface and only support the ::AccessibleExtendedComponent
interface if that makes sense for the class.