title: How to use expansion regions for loops in an activity diagram?
body: <p>I am having problems designing a proper UML activity diagram. </p>
  
  <p>I've seen similar questions and possible answers:
  <a href="https://stackoverflow.com/questions/37710695/how-to-present-a-loop-in-activity-diagram">How to present a loop in activity diagram?</a></p>
  
  <p>Even with these answers I am having doubts and my own answer doesn't correspond with the UML definitions.</p>
  
  <p>Summarization of the problem: Loop over folders and files in each folder, act upon each folder depending on its name and upon each file depending on its name. The  main problem I am having is if I am using the expansion region correctly.</p>
  
  <p>Many sources tell that an expansion region must have an input collection and an output collection. But I don't necessarily have an output collection.</p>
  
  <p>Is it automatically assumed that the Region will iterate over all items until no items are left before it goes into ActivityFinal?</p>
  
  <p>Here is a Enterprise Architect screenshot of what I've done: 
  <a href="https://i.stack.imgur.com/EWqXP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EWqXP.png" alt="enter image description here"></a></p>