Translate a list of identifiers to item ids. Identifier is a string of
        the following form:

        <model_prefix>/<model_identifier>

        where <model_prefix> is any suffix of database table of the given model
        which uniquely specifies the table, and <model_identifier> is
        identifier of the object.

        Args:
            identifiers (list[str]): list of identifiers
            language (str): language used for further filtering (some objects
                for different languages share the same item

        Returns:
            dict: identifier -> item id

def translate_identifiers(self, identifiers, language):
        """
        Translate a list of identifiers to item ids. Identifier is a string of
        the following form:

        <model_prefix>/<model_identifier>

        where <model_prefix> is any suffix of database table of the given model
        which uniquely specifies the table, and <model_identifier> is
        identifier of the object.

        Args:
            identifiers (list[str]): list of identifiers
            language (str): language used for further filtering (some objects
                for different languages share the same item

        Returns:
            dict: identifier -> item id
        """
        result = {}
        identifiers = set(identifiers)
        item_types = ItemType.objects.get_all_types()
        for item_type_id, type_identifiers in proso.list.group_by(identifiers, by=lambda identifier: self.get_item_type_id_from_identifier(identifier, item_types)).items():
            to_find = {}
            for identifier in type_identifiers:
                identifier_split = identifier.split('/')
                to_find[identifier_split[1]] = identifier
            kwargs = {'identifier__in': list(to_find.keys())}
            item_type = ItemType.objects.get_all_types()[item_type_id]
            model = ItemType.objects.get_model(item_type_id)
            if 'language' in item_type:
                kwargs[item_type['language']] = language
            for identifier, item_id in model.objects.filter(**kwargs).values_list('identifier', item_type['foreign_key']):
                result[to_find[identifier]] = item_id
        if len(result) != len(identifiers):
            raise HttpError(404, "Can't translate the following identifiers: {}".format(set(identifiers) - set(result.keys())), 'identifier_not_found')
        return result