title: Run a function every time any function in object is called
body: <p>if I have an object that looks like this:</p>
  
  <pre><code>var animal = { 
      cat: function() { alert('woof'); },
      dog: function() { alert('meow'); }
  }
  </code></pre>
  
  <p>How can I 'attach' another function to <code>animal</code> so that it runs if any function within the <code>animal</code> object is called? ( without manually calling it in each routine )</p>