protected Object readAttribute(FileObject fo, String attrName) {
        if( "removeWritables".equals( attrName ) ) {
            return new WritablesRemover( fo );
        }
        
        return super.readAttribute(fo, attrName);
    }
    
    private class WritablesRemover implements Callable {
        private FileObject fo;
        public WritablesRemover( FileObject fo ) {
            this.fo = fo;
        }
        
        public Object call() throws Exception {
            FileSystem[] fss = getDelegates();

            String path = fo.getPath();
            
            for (int i = 0; i < fss.length; i++) {
                if ((fss[i] == null) || fss[i].isReadOnly()) {
                    continue;
                }

                FileObject copy = fss[i].findResource( path );
                if( null != copy )
                    copy.delete();
            }
            return fo;
        }
        
    }