Traceback (most recent call last):
  File "/home/davide/workspaces/bddplay/src/bddplay/python/lib/python3.6/site-packages/waitress/channel.py", line 338, in service
    task.service()
  File "/home/davide/workspaces/bddplay/src/bddplay/python/lib/python3.6/site-packages/waitress/task.py", line 169, in service
    self.execute()
  File "/home/davide/workspaces/bddplay/src/bddplay/python/lib/python3.6/site-packages/waitress/task.py", line 399, in execute
    app_iter = self.channel.server.application(env, start_response)
  File "/home/davide/workspaces/bddplay/src/bddplay/python/lib/python3.6/site-packages/fanstatic/publisher.py", line 224, in __call__
    return self.app(environ, start_response)
  File "/home/davide/workspaces/bddplay/src/bddplay/python/lib/python3.6/site-packages/fanstatic/injector.py", line 76, in __call__
    result = self.injector(response.body, needed, request, response)
  File "/home/davide/workspaces/bddplay/src/bddplay/python/lib/python3.6/site-packages/fanstatic/injector.py", line 176, in __call__
    top, bottom = self.group(needed)
  File "/home/davide/workspaces/bddplay/src/bddplay/python/lib/python3.6/site-packages/fanstatic/injector.py", line 170, in group
    self.make_inclusion(needed, top_resources),
  File "/home/davide/workspaces/bddplay/src/bddplay/python/lib/python3.6/site-packages/fanstatic/injector.py", line 116, in make_inclusion
    mode=self._mode, rollup=self._rollup)
  File "/home/davide/workspaces/bddplay/src/bddplay/python/lib/python3.6/site-packages/fanstatic/inclusion.py", line 135, in __init__
    resources = sort_resources(resources)
  File "/home/davide/workspaces/bddplay/src/bddplay/python/lib/python3.6/site-packages/fanstatic/inclusion.py", line 88, in sort_resources
    return sorted(resources, key=key)
  File "/home/davide/workspaces/bddplay/src/bddplay/python/lib/python3.6/site-packages/fanstatic/inclusion.py", line 86, in key
    resource.dependency_nr,
AttributeError: 'Resource' object has no attribute 'dependency_nr'