X_ViewPort[ 'listenOnce' ]( X_EVENT_UNLOAD, this, X_Util_Window_handleEvent );\r
this[ 'listenOnce' ]( [ X_EVENT_UNLOAD, X_EVENT_KILL_INSTANCE ], X_Util_Window_handleEvent );\r
\r
X_ViewPort[ 'listenOnce' ]( X_EVENT_UNLOAD, this, X_Util_Window_handleEvent );\r
this[ 'listenOnce' ]( [ X_EVENT_UNLOAD, X_EVENT_KILL_INSTANCE ], X_Util_Window_handleEvent );\r
\r