title: Converting Sequence Diagram to Java code
body: <p>My teacher assigned an exercise which consists in translating (in the best possible way) a sequence diagram to Java code.</p>
  
  <p>This is the sequence diagram:</p>
  
  <p><a href="https://i.stack.imgur.com/DJ0hq.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DJ0hq.jpg" alt="enter image description here"></a></p>
  
  <p>And this is my attempt at solving this:</p>
  
  <pre><code>import java.util.ArrayList;
  import java.util.List;
  
  class Seminar {
      private int getMark() {
          return calculateMark();
      }
  
      private int calculateMark() {
          return 10;
      }
  }
  
  class Student {
      private List&lt;Seminar&gt; _seminars = new ArrayList&lt;&gt;();
  
      public List&lt;Seminar&gt; getSeminars() {
          return _seminars;
      }
  }
  
  class TranscriptBuilder {
      public void New(Student student) {
  
      }
  }
  </code></pre>
  
  <p>But I couldn't finish <code>TranscriptBuilder</code> as I couldn't find anything about <code>&lt;&lt;system&gt;&gt;</code> and what it means. Any suggestions, please?</p>