果level合法，返回的错误值为nil。</p>
    <h4 id="Writer.Reset">func (*Writer) <a title="View Source" href="https://github.com/golang/go/blob/master/src/compress/gzip/gzip.go?name=release#97">Reset</a> <a class="permalink" href="#pkg-index">&para;</a></h4>
    <pre class="funcdecl">func (z *<a href="#Writer">Writer</a>) Reset(w <a href="io.htm">io</a>.<a href="io.htm#Writer">Writer</a>)</pre>
    <p>Reset将z重置，丢弃当前的写入状态，并将下层输出目标设为dst。效果上等�