Document how to instantiate shared instances asynchronously

[MarcSkovMadsen]

I'm working on documenting how to use Dask with Panel including asynchronously.

I struggle figuring out what the best practice for instantiating shared objects asynchronously should be. The complication is that in a notebook you are running on an even loop and can just await in code cells. This you cannot in a server script - In a server script you can only await inside async functions.

I would like a request to describe the best practice for doing this in the Asynchronous Functions section of the user guide at https://panel.holoviz.org/user_guide/Async_and_Concurrency.html#asynchronous-functions.

The description should enable you to write code that works both in a notebook and a server app.

Example

The below code can run in a notebook but not in a server script.

import param

from dask.distributed import Client

CLIENT = await Client("tcp://127.0.0.1:64719", asynchronous=True)

class App():
    async def __init__(self):
        self._client = await Client("tcp://127.0.0.1:64719", asynchronous=True)

app = await App()

[MarcSkovMadsen]

Another example that I don't know how to do is

async def download_data(start_date=START_DATE, end_date=END_DATE):
    ...

await download_data()

[MarcSkovMadsen]

This has been solved by various improvements.