Template delimiter example doesn't work

In chapter 2, it states that delimiters can be changed very simply:

``````
You may also use double curly brackets (i.e ```{{}}```) (or any other
tag you feel comfortable with) in Microtemplates. In the case of curly
brackets, this can be done by setting the Underscore
```templateSettings``` attribute as follows:

```javascript
_.templateSettings = { interpolate : /\{\{(.+?)\}\}/g };
```
``````

But that example doesn't actually work, at least with the latest versions of Underscore and Backbone. First of all, the above suggestion will clobber the `evaluate` and `escape` properties. Second, if set so that it doesn't clobber them (`_.templateSettings.interpolate = /\{\{(.+?)\}\}/g;`), the following errors will be thrown:

```
Uncaught SyntaxError: Unexpected token = underscore.js:1156
_.template underscore.js:1156
```

Unfortunately, I don't know enough about Underscore to offer a solution.