Connection output/propagate error

[woun zoo]

Hi

I just started reading a tutorial document at http://dana.loria.fr/doc/connection.html. I'm using dana 0.5.0 version.

I was just following things as written on that page.

Whenever I use Connection function and try to print C.output() or C.propagate(), then I get error messages like the following.

Traceback (most recent call last):
  File "<pyshell#6>", line 1, in <module>
    C.propagate()
  File "/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site-packages/dana-0.5.0-py2.7.egg/dana/connection.py", line 171, in propagate
    self._actual_target += self.output()
  File "/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site-packages/dana-0.5.0-py2.7.egg/dana/connection.py", line 189, in output
    raise NotImplementedError
NotImplementedError

What should I do to solve this issue?

Thank you very much.