def METHOD_NAME(self):
    """Generate challenges groups."""
    groups = []
    authors = self.__generate_authors_map()
    for challenge in self.source.challenges:
        group = {
            "challenge": utils.slugify(challenge.title),
            "pas": [],
        }
        for pa in self.source.pas:
            if pa.id not in authors:
                group["pas"].append(pa)
            elif challenge.id not in authors[pa.id]:
                group["pas"].append(pa)
        groups.append(group)
    return groups