In Express.js, how can I render a Jade partial-view without a "response" object?

Using Express.js, I'd like to render a partial-view from a Jade template to a variable.

Usually, you render a partial-view directly to the response object:

response.partial('templatePath', {a:1, b:2, c:3})

However, since I'm inside a Socket.io server event, I don't have the "response" object.

Is there an elegant way to render a Jade partial-view to a variable without using the response object?