title: java simple association
body: <p>I am trying to add an association between Course class and Lecturer class, but I am getting an error.What am I doing wrong?</p>
  
  <p>I am adding this piece of code into the Course class so that for each course a cordinator is assigned.</p>
  
  <pre><code>public void addCordinator(Lecturer newLecturer){
      this.lecturer.add(newLecturer);
  }
  </code></pre>