docs: def _inherit_docstring(from_class):
      '''Private wrapper function to inherit docstrings from Base class
  
      Usage example:
  
      class mood(object):
          'describes typical reactions of a person in a specific mood'
          def how_are_you(self):
              'returns a typical answer to How are you? being in specific mood'
              raise NotImplementedError('No mood specified')
  
      class good_mood(mood):
          @_inherit_docstring(mood)
          def how_are_you(self):
              print 'Fine, thanks.'
  
  
  
      >>> help(good_mood.how_are_you)
  
      Help on method how_are_you in module __main__:
  
      how_are_you(self) unbound __main__.good_mood method
          returns a typical answer to How are you? being in specific mood
  
      '''
      def wrapper(method):
          funcname = method.__name__
          parent_doc = from_class.__dict__[funcname].__doc__
          if method.__doc__ is not None:
              method.__doc__ += '\n        ' + parent_doc
          else:
              method.__doc__ = parent_doc
          return method
      return wrapper