类：fs.Utf8Stream

【Class: fs.Utf8Stream】

一个优化的 UTF-8 流写入器，允许按需刷新所有内部缓冲。它能正确处理 EAGAIN 错误，并允许自定义，例如在磁盘繁忙时丢弃内容。

【An optimized UTF-8 stream writer that allows for flushing all the internal buffering on demand. It handles EAGAIN errors correctly, allowing for customization, for example, by dropping content if the disk is busy.】