title: The declared package does not match the expected package for apache-commons
body: <p>I'm trying to add apache-commons to my fresh project but I got problems with packages after importing the source.</p>
  
  <pre><code>The declared package "org.apache.commons.math" does not match
  the expected package "src.main.java.org.apache.commons.math"
  </code></pre>
  
  <p>What can I do?</p>