[Plugin: Facebook Comments for WordPress] Request Additional Permissions

Is there an easy way to request additional permissions from Facebook users who wish to post a comment using this plugin? Specifically, I want access to a user’s e-mail address when they comment on my blog, and the default behavior of the comment plugin doesn’t allow that.

I see in scripts/facebook.php, the function getLoginUrl() on line 418, does accept a parameter array of additional request parameters, but how and when is this invoked, if at all?

https://www.ads-software.com/extend/plugins/facebook-comments-for-wordpress/