private void refreshRec(File parentFile, TreeItem parentItem){
        for(File child : parentFile.listFiles()){
            if(child.isFile() && !isValidFormat(child.getName())){
                continue;
            }
            
            FilePathTreeItem item = generateFileItem(child);
            parentItem.addChild(item);
            if(child.isDirectory()){
                if(expandMemorizer.isExpanded(item.getFilePath())){
                    //refreshRec(child, item);
                    item.setExpanded(true);
                }
            }
        }
    }