@classmethod
def get_possible_model_sheet_names(cls, model):
    """ Return set of possible sheet names for a model

        Args:
            model (:obj:`Model`): Model

        Returns:
            :obj:`set`: set of possible sheet names for a model
        """
    return set(['!!' + model.__name__, '!!' + model.Meta.verbose_name, '!!' +
        model.Meta.verbose_name_plural])
