'Overrides the problem_scores member variable in order
to return empty scores for all scorable problems in the
course.'

@lazy
def problem_scores(self):

    locations = OrderedDict()
    for block_key in self.course_data.structure.post_order_traversal(filter_func=possibly_scored, start_node=self.location):
        block = self.course_data.structure[block_key]
        if getattr(block, 'has_score', False):
            problem_score = get_score(submissions_scores={}, csm_scores={}, persisted_block=None, block=block)
            if (problem_score is not None):
                locations[block_key] = problem_score
    return locations
