title: 'NSInvalidArgumentException', reason: 'data parameter is nil'
body: <p>XCode newbie here and i have been trying to figure out why the following is happening...</p>
  
  <p>With the way the code is currently written, i keep getting 'NSInvalidArgumentException'. </p>
  
  <blockquote>
    <p>reason: 'data parameter is nil' in xcode. The url works fine on the browser. </p>
  </blockquote>
  
  <p>When I remove the "filters=%7B%22region%22%3A%22CA%22%7D" part of the url, it works fine in Xcode, but when this section of the url is included, that's when I get the error message. I have tried using \" in replacement of the %22 but still nothing. Any suggestions are greatly appreciated. </p>
  
  <pre><code>NSURL *url = [NSURL URLWithString:[@"http://api.v3.factual.com/t/restaurants-us?q=peets+coffee&amp;filters=%7B%22region%22%3A%22CA%22%7D&amp;KEY=p7kwKMFUSyVi64FxnqWmeSDEI41kzE3vNWmwY9Zi"stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
  NSData *data = [NSData dataWithContentsOfURL: url];
  </code></pre>