docs: def patch_connection(filename=':memory:'):
      """
      ``filename``: rlite filename to store db in, or memory
      Patch the redis-py Connection and the
      static from_url() of Redis and StrictRedis to use RliteConnection
      """
  
      if no_redis:
          raise Exception("redis package not found, please install redis-py via 'pip install redis'")
  
      RliteConnection.set_file(filename)
  
      global orig_classes
  
      # already patched
      if orig_classes:
          return
  
      orig_classes = (redis.connection.Connection,
                      redis.connection.ConnectionPool)
  
      _set_classes(RliteConnection, RliteConnectionPool)