def _get_entities(self, fields: Iterable[Union[(Entity, str)]]) -> List[Entity]:
    from olo.model import ModelMeta
    if (not isinstance(fields, (list, tuple, set))):
        fields = [fields]
    res = []
    for field in fields:
        if isinstance(field, str_types):
            field_ = self._model_class._olo_get_field(field)
            if (field_ is None):
                raise ORMError(f'{friendly_repr(field)} is not a valid field in Model {self._model_class.__name__}')
            field = field_
        if (not isinstance(field, (ModelMeta, Field, Function))):
            raise ORMError(f'{field} is an not valid entity!')
        res.append(field)
    return res
def _get_entities(self, fields: Iterable[Union[(Entity, str)]]) -> List[Entity]:
    from olo.model import ModelMeta
    if (not isinstance(fields, (list, tuple, set))):
        fields = [fields]
    res = []
    for field in fields:
        if isinstance(field, str_types):
            field_ = self._model_class._olo_get_field(field)
            if (field_ is None):
                raise ORMError(f'{friendly_repr(field)} is not a valid field in Model {self._model_class.__name__}')
            field = field_
        if (not isinstance(field, (ModelMeta, Field, Function))):
            raise ORMError(f'{field} is an not valid entity!')
        res.append(field)
    return res