title: Split a text without whitespaces by words in list
body: <p>I have three lists, that I have merged into one list </p>
  
  <pre><code>    static List allLists = Stream.of(list1, list2, list3)
          .flatMap(Collection::stream)
          .collect(Collectors.toList());
  </code></pre>
  
  <p>I have user input without whitespaces</p>
  
  <pre><code>String = "HelloIwanttobookanonlineseminaratyourcompany"
  </code></pre>
  
  <p>All the words in the user input <code>String</code> are already in <code>allLists</code>. I want to iterare over <code>allLists</code> and insert whitespaces into the String, with every word found. The result should be:</p>
  
  <pre><code>String = "Hello I want to book an online seminar at your company"
  </code></pre>
  
  <p>Is there an easy solution I miss?</p>