question: public long createBackBuffer ( X11ComponentPeer peer , int numBuffers , BufferCapabilities caps ) throws AWTException { if ( ! X11GraphicsDevice . isDBESupported ( ) ) { throw new AWTException ( "Page flipping is not supported" ) ; } if ( numBuffers > 2 ) { throw new AWTException ( "Only double or single buffering is supported" ) ; } BufferCapabilities configCaps = getBufferCapabilities ( ) ; if ( ! configCaps . isPageFlipping ( ) ) { throw new AWTException ( "Page flipping is not supported" ) ; } long window = peer . getContentWindow ( ) ; int swapAction = getSwapAction ( caps . getFlipContents ( ) ) ; return createBackBuffer ( window , swapAction ) ; }
target:  Attempts to create an XDBE-based backbuffer for the given peer.  If the requested configuration is not natively supported, an AWTException is thrown.  Otherwise, if the backbuffer creation is successful, a handle to the native backbuffer is returned.