Meteor's email package attachment

Question

I'm poking around http://docs.meteor.com/#email . It's pretty easy to send flat emails, but how can an attachment be added? There's a comment in email.js:136 code:

// XXX support attachments (once we have a client/server-compatible binary 
// Buffer class)

Also Email uses MailComposer, which has method addAttachment(). Still it makes no sense about passing the attachment in Email.send() function.

Any suggestions?