title: How to add a value to the inside List<String> from an List<List<String>>?
body: <p>I have:</p>
  <pre><code>List&lt;List&lt;String&gt;&gt; finalInfo = new ArrayList&lt;&gt;();
  </code></pre>
  <p>And I am trying to put in the index 4 a value from another list of list of strings, populated named tempInfo.</p>
  <pre><code>finalInfo.get(0).add(4, tempInfo.get(0).get(4))
  </code></pre>
  <p>The following error is thrown:</p>
  <blockquote>
  <p>java.lang.UnsupportedOperationException</p>
  </blockquote>
  <p>Thanks for your help,</p>
  <p>Best regards.</p>