def __init__(self, delta, clip=True):
        """
        Args:
            delta (float): Randomly add a value within [-delta,delta]
            clip (bool): clip results to [0,255] even when data type is not uint8.
        """
        super(Brightness, self).__init__()
        assert delta > 0
        self._init(locals())

        Args:
            delta (float): Randomly add a value within [-delta,delta]
            clip (bool): clip results to [0,255] even when data type is not uint8.
        
tensorpack/dataflow/imgaug/imgproc.py