Revert removing of SyncToAsync.get_current_task

[legau]

SyncToAsync.get_current_task was removed in #367 where it was not documented and introduces regressions in our code base

[andrewgodwin]

This was never a publicly-documented API; may I ask what type of code was relying on it? We can add it back but it's also mostly just dispatching to asyncio.

[carltongibson]

@legau This is unused, so at the least you'll want to add a test case covering it to prevent a regression in the future.

You may be better off using asyncio.current_task directly. Is there a reason not to do that? (Other than the obvious undocumented breakage...)

[carltongibson]

Cc @jthorniley FYI (And if you have any thought...)

[legau]

Hi, this is used in an obscure piece of an internal lib of ours. We are going to replace it by asyncio.current_task, could we make this deprecated for now ?

[carltongibson]

@legau It's probably easiest if you pin to version 3.7.2 whilst you work on the adjustment. That's a one-line requirements change for you, vs quite a lot of disruption to re-add, release, and immediately deprecate the method, which as Andrew notes was undocumented private API anyway.

[legau]

I guess it's easier I'm closing the PR. However I disagree on it being a private method, it is a publicly named method of a documented publicly exposed class.