Client sample code from aiohttp docs is complaining about missing connector

Question

I am trying to run the below aiohttp client sample code straight out of aiohttp docs but it is throwing an exception.

import aiohttp
import asyncio

async def main():

    async with aiohttp.ClientSession() as session:
        async with session.get('http://python.org') as response:

            print("Status:", response.status)
            print("Content-type:", response.headers['content-type'])

            html = await response.text()
            print("Body:", html[:15], "...")

loop = asyncio.get_event_loop()
loop.run_until_complete(main())

Exception

Traceback (most recent call last):
  File "aiohttp-test.py", line 16, in <module>
    loop.run_until_complete(main())
  File "/Users/waseem/.pyenv/versions/3.8.4/lib/python3.8/asyncio/base_events.py", line 616, in run_until_complete
    return future.result()
  File "aiohttp-test.py", line 6, in main
    async with aiohttp.ClientSession() as session:
TypeError: __init__() missing 1 required positional argument: 'connector'

Versions of the required libs installed

Does anyone know what could be happening here?