question: protected void checkOffscreenImage ( Dimension d ) { if ( doubleBuffered ) { if ( offscreen == null || offscreen . getWidth ( ) != d . width || offscreen . getHeight ( ) != d . height ) { offscreen = new BufferedImage ( d . width , d . height , BufferedImage . TYPE_INT_ARGB ) ; offscreenG2d = offscreen . createGraphics ( ) ; } } }
target:  Ensure that, if doubleBuffering is enabled, the offscreen image buffer exists and is the correct size.