source.startProduction (painter); source.removeConsumer (painter);
if (source != null) { source.startProduction (painter); source.removeConsumer (painter); }
  startProduction (GtkImagePainter painter)  {    if (isLoaded)      {	painter.setDimensions (width, height);	painter.setPixels (0, 0, width, height, model, pixelCache, 0, width);      }    else      {	source.startProduction (painter);	source.removeConsumer (painter);      }  }