title: IntelliJ: cannot resolve smybol in "org.apache.commons.lang3.tuple.ImmutablePair"
body: <p>I am working on a web visualisation for a given project (db with genes, proteins, task is to do some nice visualisation with springboot and thymeleaf). The project was provided with all files, yet I am missing some libraries (also leading to some errors in the code ofc).</p>
  
  <p>When trying to import:</p>
  
  <pre><code>import org.apache.commons.lang3.tuple.ImmutablePair;
  import org.apache.commons.lang3.tuple.Pair;
  </code></pre>
  
  <p>lang3 gives me a "cannot resolve symbol" error and automatically searching jars on web results in "no jars found".I found the lang3-jar manually and successfully added it to the project library. When importing:</p>
  
  <pre><code>import org.apache.commons.lang3.*; 
  </code></pre>
  
  <p>All errors for tuple.Pair-usage are gone. Yet, usage of ImmutablePair still results in a "cannot resolve symbol" error.</p>
  
  <p>Firstly, I am confused and now unsure, if my knowledge of imports is correct. I learned, if for example you import something.anything.x and something.anything.y, you could also just import something.anything.*; and x and y would be covered. </p>
  
  <p>Secondly, if needed, where do I find the jars I need (I could not find them yet).</p>
  
  <p>Thanks :)</p>