title: Error when using box-java-sdk
body: <p>I have tried to create App user with box-java-sdk example in that link
  <a href="https://github.com/box/box-java-sdk" rel="nofollow">https://github.com/box/box-java-sdk</a></p>
  
  <p>And here is the code parameters :</p>
  
  <pre><code>private static final String CLIENT_ID = "qve5jn#############yz6azyh7tabfs";
  private static final String CLIENT_SECRET = "kELXWLp8e#############KjKOayc";
  private static final String ENTERPRISE_ID = "946313";
  private static final String PUBLIC_KEY_ID = "l925y3o8";
  private static final String PRIVATE_KEY_FILE = "/home/baddar/.ssh/private_key.pem";
  private static final String PRIVATE_KEY_PASSWORD = "hello";
  private static final String APP_USER_NAME = "mbaddar1";
  private static final int MAX_CACHE_ENTRIES = 100;
  </code></pre>
  
  <p>However , I always have the error </p>
  
  <blockquote>
    <p>{"error":"invalid_grant","error_description":"Please check the 'exp'
    claim."}</p>
  </blockquote>
  
  <p>Any ideas ?</p>