title: Retrieving cached oauth token with packages httr, twitteR, and streamR
body: <p>The only way I've found to get myself authenticated with the twitter API is the following:</p>
  
  <pre><code>library(twitteR)
  
  setup_twitter_oauth(consumer_key = "a", 
                  consumer_secret = "b", 
                  access_token = "c", 
                  access_secret = "d")
  </code></pre>
  
  <p>After running this, I can use all functions in twitteR just fine. However, I would also like to use the streamR package, which needs the token as an OAuth object: </p>
  
  <pre><code>filterStream("tweets.json", track = c("Obama", "Biden"), timeout = 20, oauth=my_oauth)
  </code></pre>
  
  <p>From what I gather, the setup_twitter_oauth function above is a wrapper around some httr functions to get my authorization token. This token is cached in my working directory as a file called ".httr-oauth". My question is: how do I load this file into R, such that I get an OAuth object that I can use with streamR?</p>