add the given update listener . concode_field_sep Revision latestRevision concode_elem_sep CopyOnWriteArrayList<UpdateListener> listeners concode_elem_sep String errorMessage concode_elem_sep State state concode_field_sep void setLatestAvailableRevision concode_elem_sep void setErrorMessage concode_elem_sep void handleException concode_elem_sep boolean isUpdateReadyToBeApplied concode_elem_sep void enterState concode_elem_sep boolean isUpdateApplied concode_elem_sep void notifyListeners concode_elem_sep boolean isUpdateAvailable concode_elem_sep boolean isDownloadingUpdate concode_elem_sep boolean isIdle concode_elem_sep void removeListener concode_elem_sep void notify concode_elem_sep void notify concode_elem_sep void notify concode_elem_sep void notify concode_elem_sep void notify concode_elem_sep void notify concode_elem_sep void notify concode_elem_sep void notify concode_elem_sep void notify concode_elem_sep void notify concode_elem_sep void notify
void function ( UpdateListener arg0 ) { if ( ! listeners . contains ( arg0 ) ) { listeners . add ( arg0 ) ; } }