def transform(self, results: Dict) -> dict:
        """The transform function of :class:`ZeroCenterPose`.

        See ``transform()`` method of :class:`BaseTransform` for details.

        Args:
            results (dict): The result dict

        Returns:
            dict: The result dict.
        """

        keypoints = results['keypoints']
        if 'keypoints_visible' in results:
            keypoints_visible = results['keypoints_visible']
        else:
            keypoints_visible = np.ones(keypoints.shape[:-1], dtype=np.float32)
        lifting_target = results['lifting_target']
        if 'lifting_target_visible' in results:
            lifting_target_visible = results['lifting_target_visible']
        else:
            lifting_target_visible = np.ones(
                lifting_target.shape[:-1], dtype=np.float32)

        if np.random.rand() <= self.flip_prob:
            if 'flip_indices' not in results:
                flip_indices = list(range(self.num_keypoints))
            else:
                flip_indices = results['flip_indices']

            # flip joint coordinates
            keypoints, keypoints_visible = flip_keypoints_custom_center(
                keypoints, keypoints_visible, flip_indices,
                **self.keypoints_flip_cfg)
            lifting_target, lifting_target_visible = flip_keypoints_custom_center(  # noqa
                lifting_target, lifting_target_visible, flip_indices,
                **self.target_flip_cfg)

            results['keypoints'] = keypoints
            results['keypoints_visible'] = keypoints_visible
            results['lifting_target'] = lifting_target
            results['lifting_target_visible'] = lifting_target_visible

            # flip horizontal distortion coefficients
            if self.flip_camera:
                assert 'camera_param' in results, \
                    'Camera parameters are missing.'
                _camera_param = deepcopy(results['camera_param'])

                assert 'c' in _camera_param
                _camera_param['c'][0] *= -1

                if 'p' in _camera_param:
                    _camera_param['p'][0] *= -1

                results['camera_param'].update(_camera_param)

        return results
The transform function of :class:`ZeroCenterPose`.

        See ``transform()`` method of :class:`BaseTransform` for details.

        Args:
            results (dict): The result dict

        Returns:
            dict: The result dict.
        
mmpose/mmpose/datasets/transforms/pose3d_transforms.py