code: private String genCacheFilePath(String node) {
  		checkFolderExistence();
  		StringBuilder builder = new StringBuilder();
  		builder.append(localCachePath);
  		builder.append(File.separatorChar);
  		builder.append(node);
  		builder.append(SUFFIX);
  
  		return builder.toString();
  	}
docs: 计算本地缓存文件位置
  
  @param node
  @return