如何添加twitter的搜索引擎

我知道有一个
Twitter Search 20090106

https://addons.mozilla.org/en-US/firefox/addon/10279

不过那并不是我最想要的

我想修改下，用以下代码的搜索引擎怎么办？

<SearchPlugin xmlns="http://www.mozilla.org/2006/browser/search/" xmlns:os="http://a9.com/-/spec/opensearch/1.1/">
<os:ShortName>Twitter Search</os:ShortName>
<os:Description>Realtime Twitter Search</os:Description>
<os:InputEncoding>UTF-8</os:InputEncoding>
<os:Image width="16" height="16">data:image/x-icon;base64,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</os:Image>
<SearchForm>https://twitter.com/</SearchForm>
<os:Url type="text/html" method="GET" template="https://twitter.com/#search?q={searchTerms}">
</os:Url>
</SearchPlugin>

从来都用Add to search bar来添加搜索引擎，它比OpenSearchFox好在添加对话框就可以指定关键字，并且前者是一个还留在AMO上的扩展

奇怪，又可以了。。。
好像是我之前用Web Search Pro的缘故。。。
残念。