code: function getTweets(T, user_id, max_tweets, finish) {
    return getTweetsIt(T, user_id, [], max_tweets, finish);
  }
docs: /*
  getTweets(T, user_id, max_tweets, finish)
  ***********************
  Gets all tweets of given user and calls callback with the array of tweets.
  Possibly waits until the max #requests/15min rate has passed, so can take a while.