def on_epoch_end(self, runner: "IRunner"):
        """Unwraps loaders for current epoch.

        Args:
            runner: current runner
        """
        runner.loaders = {
            key: value.origin if isinstance(value, BatchLimitLoaderWrapper) else value
            for key, value in runner.loaders.items()
        }
Unwraps loaders for current epoch.

        Args:
            runner: current runner
        
catalyst/callbacks/batch_overfit.py