How to mock a streaming API with RSpec?

I'm playing around with the tweetstream gem, which simplifies interaction with the Twitter streaming API. I'm streaming all tweets just like the code example shown on the gem's page:

TweetStream::Client.new.sample do |status|
  puts "#{status.text}"
end

I've put this in a #capture method with some simple logic to run the stream for only a few seconds and capture all the tweets (the status.text strings) in an array. I'm not sure if I should use VCR here, either.

I want to write unit tests for #capture. How would I stub out the stream of tweets? I'm guessing I'll have store tweets in either a file or a StringIO object, but I don't know how to write the mock to handle whatever TCP interaction is going on with the streaming API.