title: _.memoize applicable scenario is what?
body: <p>I learning underscorejs _.memoize method, I want to know his applicable scenario.
  dizzy! dizzy! not to understand the API what is saying.</p>
  
  <pre><code>var fibonacci = _.memoize(function(n) {
      return n &lt; 2 ? n: fibonacci(n - 1) + fibonacci(n - 2);
  });
  </code></pre>