| AbstractPreferences | This class provides a skeletal implementation of the  Preferences
 class, greatly easing the task of implementing it. | 
| BackingStoreException | Thrown to indicate that a preferences operation could not complete because
 of a failure in the backing store, or a failure to contact the backing
 store. | 
| InvalidPreferencesFormatException | Thrown to indicate that an operation could not complete because
 the input did not conform to the appropriate XML document type
 for a collection of preferences, as per the  Preferences
 specification. | 
| NodeChangeEvent | An event emitted by a Preferencesnode to indicate that
 a child of that node has been added or removed. | 
| NodeChangeListener | A listener for receiving preference node change events. | 
| PreferenceChangeEvent | An event emitted by a Preferencesnode to indicate that
 a preference has been added, removed or has had its value changed. | 
| PreferenceChangeListener | A listener for receiving preference change events. | 
| Preferences | A node in a hierarchical collection of preference data. |