if (presentation != null) presentation.deIconify();
if (presentation == null) { initChannelData(); buildPresentation(); } presentation.deIconify();
    private void handleDisplayViewerRelatedAgents(DisplayViewerRelatedAgent                                                 response)    {        if (response.isOnOff()) {            if (presentation != null) presentation.deIconify();        } else {            if (presentation != null) removePresentation();         }    }