1. Create content type which is not a container.
2. Create two content items (item1 and item2) using content type from previous step.
3. Go to Locations tab from item2 and click [+] button.
4. Choose item1 and confirm - now item1 has a child. In v1 it is impossible to select an item which is not a container. In addition, in that case, item1 can swap locations with another containers.