Is _get_running_loop() a public or it is actually an implementation detail.
I thought the second sentence is right.

_get_running_loop() is a part of the API intended to be used by alternative event loops like uvloop and frameworks like Twisted. When we added it we decided to keep it undocumented, but export it as part of asyncio.__all__.

I've reconsidered removing the function -- let's keep it as it.

I've changed the proposed get_running_loop() to raise a RuntimeError if there's no running event loop.