python-django-treebeard 4.3+dfsg-1 (amd64 binary) in ubuntu cosmic

 Django Treebeard is a library that implements efficient data structures for
 storing hierarchical data in a database using the Django web development
 framework.
 .
 It currently includes 3 different tree implementations: adjacency list,
 materialized path and nested sets. Each one has it's own strengths and
 weaknesses but share the same API, so it’s easy to switch between them.