def METHOD_NAME(
    self,
    specs: Iterable[ExternalResourceSpec],
    account_filter: Optional[str] = None,
) -> None:
    """
    Add external resource specs
    :param specs: external resource specs to add
    :param account_filter: an account name that can optionally be used to filter out
                           any resources that don't match the account. If omitted,
                           all specs will be added.
    """
    for spec in specs:
        # If using an account filter and the account name doesn't match, skip the
        # resource.
        if account_filter and account_filter != spec.provisioner_name:
            continue
        try:
            self._clients[spec.provisioner_name].add_spec(spec)
        except KeyError:
            raise ClientNotRegisteredError(
                f"There aren't any clients registered with the account name: {spec.provisioner_name}"
            )
        self.resource_spec_inventory[spec.id_object()] = spec