Idea for contextvars-based API design for ring-cache

ring-contextvars.py

import redis
from ring import Ring
import contextvars

redis_connection = contextvars.ContextVar('redis_connection', None)
ring = Ring(...)

class A:
  @ring.redis(redis_connection, ...)
  def get_something(self):
    ...

if __name__ == '__main__':
  redis_connection.set(redis.Redis(...))
  a = A()
  print(a.get_something())
  print(a.get_something())