def get_data_info(self, idx: int) -> dict:
        """Get annotation by index.

        Args:
            idx (int): Global index of ``CombinedDataset``.
        Returns:
            dict: The idx-th annotation of the datasets.
        """
        subset_idx, sample_idx = self._get_subset_index(idx)
        # Get data sample processed by ``subset.pipeline``
        data_info = self.datasets[subset_idx][sample_idx]

        # Add metainfo items that are required in the pipeline and the model
        metainfo_keys = [
            'upper_body_ids', 'lower_body_ids', 'flip_pairs',
            'dataset_keypoint_weights', 'flip_indices'
        ]

        for key in metainfo_keys:
            data_info[key] = deepcopy(self._metainfo[key])

        return data_info
Get annotation by index.

        Args:
            idx (int): Global index of ``CombinedDataset``.
        Returns:
            dict: The idx-th annotation of the datasets.
        
mmpose/mmpose/datasets/dataset_wrappers.py