code: function sample(array, n, randomSource) {
          // shuffle the original array using a fisher-yates shuffle
          var shuffled = shuffle(array, randomSource);
  
          // and then return a subset of it - the first `n` elements.
          return shuffled.slice(0, n);
      }
docs: # sample  Create a [simple random sample](http://en.wikipedia.org/wiki/Simple_random_sample) from a given array of `n` elements.