TypeError with async await syntax compared to equivalent @asyncio.coroutine syntax

async_hello_world.py

"""
  Was running into the following error with the new async await syntax, where the equivalent @asyncio.coroutine did not give an error.
  But this has since resolved, liekly due to an import problem or library version:
  
  ...
  loop.run_until_complete(hello_world())
  File "/usr/local/lib/python3.5/site-packages/asyncio-3.4.3-py3.5.egg/asyncio/base_events.py", line 296, in run_until_complete
    future = tasks.async(future, loop=self)
  File "/usr/local/lib/python3.5/site-packages/asyncio-3.4.3-py3.5.egg/asyncio/tasks.py", line 516, in async
    raise TypeError('A Future or coroutine is required')
TypeError: A Future or coroutine is required
"""
import asyncio


def async_hw():
    async def hello_world():
        print("Hello World!")
    loop = asyncio.get_event_loop()
    loop.run_until_complete(hello_world())
    loop.close()


def coroutine_hw():
    @asyncio.coroutine
    def hello_world():
        print("Hello World!")
    loop = asyncio.get_event_loop()
    loop.run_until_complete(hello_world())
    loop.close()