def cluster(self, vectors, assign_clusters=False):
        raise NotImplementedError()
Error result as generator by the runner container is of the form
dataset/ETHPy150Open nltk/nltk/nltk/cluster/api.py/ClusterI.cluster--crossover with--dataset/ETHPy150Open StackStorm/st2contrib/packs/hubot/actions/post_result.py/format_possible_failure_result