How can I call a method on a handler created by logging.config.dictConfig in Python?

I'm trying to set up a particular logging scheme for an application I'm building. For it, I want to be able to rotate logs arbitrarily on a custom condition. As such, the built-in options of rotating based on time (using TimedRotatingFileHandler) or log size (using RotatingFileHandler) are not sufficient. Both TimedRotatingFileHandler and RotatingFileHandler do however have the method doRollover which I could use to implement what I want. The problem comes from that I'm using logging.config.dictConfig to set up my log configuration, like so:

config = {"version": 1,"formatters": {"default_formatter": {"format": logging.BASIC_FORMAT,        },    },"handlers": {"file": {"class": "logging.handlers.RotatingFileHandler","level": "NOTSET","formatter": "default_formatter","backupCount": 5,"filename": "log.txt","encoding": "utf8",        },    },"loggers": {"": {"level": "NOTSET","handlers": ["file"],        },    },}logging.config.dictConfig(config)

This way, logging.config.dictConfig is responsible for instantiating RotatingFileHandler, and so I never get the chance to retain a reference to the class instance (i.e., the object). As such, it is not clear how I could go about calling methods upon the object.

How could I go about calling a method (in my case, doRollover) on an object instantiated as a handler by logging.config.dictConfig? Alternatively, if that is not possible, how can I manually provide a handler object that I have instantiated by calling the constructor directly given this configuration?