def METHOD_NAME(ctx, grad_voxel_feats, grad_voxel_coors=None):
    (feats, voxel_feats, point2voxel_map,
     voxel_points_count) = ctx.saved_tensors
    grad_feats = torch.zeros_like(feats)
    # TODO: whether to use index put or use cuda_backward
    # To use index put, need point to voxel index
    ext_module.dynamic_point_to_voxel_backward(
        grad_feats, grad_voxel_feats.contiguous(), feats, voxel_feats,
        point2voxel_map, voxel_points_count, ctx.reduce_type)
    return grad_feats, None, None