Support both asyncio and synchronous callers

I'm the author of Stem, Tor's python library. Recently we migrated to asyncio, but desire to still be usable by synchronous callers.

We wrote a mixin that transparently makes any class usable by both asyncio and synchronous callers...

import asyncio
import stem.util.asyncio

class Example(stem.util.asyncio.Synchronous):
  async def hello(self):
    return 'hello'

def sync_demo():
  instance = Example()
  print('%s from a synchronous context' % instance.hello())
  instance.stop()

async def async_demo():
  instance = Example()
  print('%s from an asynchronous context' % await instance.hello())
  instance.stop()

sync_demo()
asyncio.run(async_demo())

Is there a better way to approach this?

Our wider ecosystem seem to be forking networking libraries into sync/async variants, with requests and AIOHTTP as the most prominent. Are there any libraries out there that demonstrate good support for both kinds of callers without duplicating their API?

Thanks!