title: Using apply on Stripe Node.js library functions
body: <p>In my Node.js application I'm trying to use apply to make a function call in the Stripe library since the access token parameter is optional. However, I'm getting a type error.</p>
  
  <pre><code>var args = [data];
  if(accessToken) {
      args.push(accessToken);
  }
  args.push(function(err, customer) {
      ...
  });
  stripe.customers.create.apply(this, args);
  </code></pre>
  
  <pre class="lang-none prettyprint-override"><code>Uncaught TypeError: Cannot call method 'createUrlData' of undefined
    at /home/codio/workspace/node_modules/stripe/lib/StripeMethod.js:33:24
  </code></pre>
  
  <p>I believe this a result of using strict mode but let me know if this is expected behavior. I'm using version 2.8.0 of the Stripe Node.js library.</p>