title: UML Sequence Diagram: System returns a list
body: <p>I'm doing an SSD between a user and a youtube like system, and I have a method where the user asks the system to show the playlist: showPlaylist()</p>
  
  <p>The system returns a list of every video on the playlist and also each video's run time.</p>
  
  <p>I'm having trouble representing this. I'm not returning multiple attributes of one single video, I'm returning a list of videos and specifying which of its atributtes I show.</p>
  
  <p>I tought about doing a loop where it returns run times but I don't know what the exit condition would be.</p>
  
  <p>Or am I overthinking this and I should just return a single variable, my list?</p>
  
  <p>Help is appreciated, but the text for my exercise is in portuguese and already a bit confusing so translating it all would be a pain.</p>