window 
   r 
   (logior  #$NSTitledWindowMask 
            #$NSClosableWindowMask  
            #$NSMiniaturizableWindowMask 
            #$NSResizableWindowMask)
   ...))
    </pre>

    <p>Like the style masks, the <code>NSBackingStoreType</code> value
    is a named constant that describes which drawing strategy Cocoa
    should use for the contents of the window. The value can
    be <code>NSBackingStoreRetained</code>, <code>NSBackingStoreNonretained</code>,
    or <code>NSBackingStoreBuffered</code>.