def resolve_relation_alias(
        self, from_model: Union[Type["Model"], Type["ModelRow"]], relation_name: str
    ) -> str:
        """
        Given model and relation name returns the alias for this relation.

        :param from_model: model with relation defined
        :type from_model: source Model
        :param relation_name: name of the relation field
        :type relation_name: str
        :return: alias of the relation
        :rtype: str
        """
        alias = self._aliases_new.get(f"{from_model.get_name()}_{relation_name}", "")
        return alias

        Given model and relation name returns the alias for this relation.

        :param from_model: model with relation defined
        :type from_model: source Model
        :param relation_name: name of the relation field
        :type relation_name: str
        :return: alias of the relation
        :rtype: str
        
ormar/relations/alias_manager.py