using webmock to mock curb Curl::easy

Question

I have a RoR site using curb, and I currently have the line:

- password =  Curl::Easy.perform("http://www.dinopass.com/password/simple").body_str

I am already including webmock, and I see that it claims that it can mock this case. But I don't see any examples of how it's actually done... I'm testing with cucumber and Capybara in case that matters.