public static void removeListener(final DiagnosticListener listener){
  if (listener != null) {
    listener.close();
  }
  LISTENERS.remove(listener);
}

public static void removeListener ( final DiagnosticListener listener ) { if ( listener != null ) { listener . close ( ) ; } LISTENERS . remove ( listener ) ; }
remove a listener from those notified whenever a diagnostic occurs . requests to remove a listener not currently registered are ignored .
