title: External library usage in xcode
body: <p>I am following this tutorial for import socket.io to swift. <a href="http://socket.io/blog/socket-io-on-ios/" rel="nofollow noreferrer">http://socket.io/blog/socket-io-on-ios/</a></p>
  
  <p>I did everything in the tutorial but I am getting this error:</p>
  
  <blockquote>
    <p>Use of unresolved identifier 'SocketIOClient'</p>
  </blockquote>
  
  <p>for this piece of code:</p>
  
  <pre><code>let socket = SocketIOClient(socketURL: "localhost:8900") 
  </code></pre>
  
  <p>My structure:</p>
  
  <p><img src="https://i.stack.imgur.com/DZh2i.png" alt="enter image description here"></p>
  
  <p>How can I resolve this problem ?</p>