Changed GHOPComment model to inherit from base model.
All the properties are specific to the GHOPComment model. The GHOPComment
model is also made ID based. Changes changes property from StringProperty
to StringListProperty.
Coverage: code coverage testing for Python
Coverage.py is a Python module that measures code coverage during test execution.
It uses the code analysis tools and tracing hooks provided in the Python standard
library to determine which lines are executable, and which have been executed.
For more information, see http://nedbatchelder.com/code/modules/coverage.html