def get_fold(dict_actors_per_fold, actor_id):
    """
          Get the fold that the actor belongs to.

          :param dict_actors_per_fold[dict] Map with the fold number as key (ranging from 1 to 5) and the list of actors in that test fold as the value of the dict.
          :param actor_id:[int] Id of the actor. We want to obtain the fold where it belongs
      """
    for fold_key in list(dict_actors_per_fold.keys()):
        if(actor_id in dict_actors_per_fold[fold_key]):
            return fold_key