else:
                return await runnable.ainvoke(input, config, **kwargs)
        runnables = [self.runnables[key] for key in keys]
        configs = get_config_list(config, len(inputs))
        return await gather_with_concurrency(
            configs[0].get("max_concurrency"),
            *(
                ainvoke(runnable, input, config)
                for runnable, input, config in zip(runnables, actual_inputs, configs)
            ),
        )
[docs]    def stream(
        self,
        input: RouterInput,
        config: Optional[RunnableConfig] = None,
        **kwargs: Optional[Any],
    ) -> Iterator[Output]:
        key = input["key"]
        actual_input = input["input"]
        if key not in self.runnables:
            raise ValueError(f"No runnable associated with key '{key}'")
        runnable = self.runnables[key]
        yield from runnable.stream(actual_input, config)
[docs]    async def astream(
        self,
        input: RouterInput,
        config: Optional[RunnableConfig] = None,
        **kwargs: Optional[Any],
    ) -> AsyncIterator[Output]:
        key = input["key"]
        actual_input = input["input"]
        if key not in self.runnables:
            raise ValueError(f"No runnable associated with key '{key}'")
        runnable = self.runnables[key]
        async for output in runnable.astream(actual_input, config):
            yield output