title: Error with org.slf4j.Logger
body: <p>I have an error when I import the <code>org.slf4j.*</code> packages.</p>
  
  <pre><code>import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  </code></pre>
  
  <p>Do you have any ideas where it came from ?</p>