def __call__(self, img):
        """
        Args:
            img (numpy.ndarray (C x H x W)): Image to be flipped.

        Returns:
            img (numpy.ndarray (C x H x W)): flipped image.
        """
        if not(_is_numpy_image(img)):
            raise TypeError('img should be ndarray. Got {}'.format(type(img)))

        if self.do_flip:
            return np.fliplr(img)
        else:
            return img

        Args:
            img (numpy.ndarray (C x H x W)): Image to be flipped.

        Returns:
            img (numpy.ndarray (C x H x W)): flipped image.
        
dataloaders/transforms.py