def METHOD_NAME(self):
    """
    return: contribution_assignment
        (key is client_index; value is the client's relative contribution);
        the sum of values in the dictionary is equal to 1
    """
    contribution_assignment = dict()
    for t, shapley_t in self.shapley_values_by_round.items():
        for id in shapley_t:
            if self.SV.get(id):
                self.SV[id].append(shapley_t[id])
            else:
                self.SV[id] = [shapley_t[id]]
    keys = range(1, self.args.client_num_in_total + 1)
    for id in keys:
        self.SV_summed[id] = np.sum(self.SV[id])
    total_sv = sum(self.SV_summed.values())
    for id in keys:
        contribution_assignment[id] = self.SV_summed[id] / total_sv
    return contribution_assignment