"literalMidWordUnderscores:true" didn't work

[iRuxu]

My options like this blow

const converter = new showdown.Converter({
    parseImgDimension: true,
    strikethrough: true,
    tables: true,
    tasklists: true,
    simpleLineBreaks: true,
    openLinksInNewWindow: true,
    backslashEscapesHTMLTags: true,
    literalMidWordUnderscores:true,
    extensions: ['codehighlight']
});
export default converter;

And all other features work well . But literalMidWordUnderscores didn't work. For example，There is a paragraph

任何类，只需要定义一个call()方法，就可以直接对实例进行调用。

And the "call" will be ouputed like"call" and wrapped by "strong" tag.

Could you help me?