How to use the implicit._nearest_neighbours.NearestNeighboursScorer function in implicit

def fit(self, weighted, show_progress=True):
        """ Computes and stores the similarity matrix """
        self.similarity = all_pairs_knn(weighted, self.K,
                                        show_progress=show_progress,
                                        num_threads=self.num_threads).tocsr()
        self.scorer = NearestNeighboursScorer(self.similarity)

def __setstate__(self, state):
        self.__dict__.update(state)
        if self.similarity is not None:
            self.scorer = NearestNeighboursScorer(self.similarity)
        else:
            self.scorer = None

def load(cls, filename):
        # numpy.save automatically appends a npz suffic, numpy.load doesn't apparently
        if not filename.endswith(".npz"):
            filename = filename + ".npz"

        m = numpy.load(filename)
        similarity = csr_matrix((m['data'], m['indices'], m['indptr']), shape=m['shape'])

        ret = cls()
        ret.similarity = similarity
        ret.scorer = NearestNeighboursScorer(similarity)
        ret.K = m['K']
        return ret