def METHOD_NAME(self):
    sidecar_info = {}
    sidecar_info["bundle_ids"] = {}
    dps = np.zeros(len(self.sft.streamlines))
    for ii, bundle_name in enumerate(self.bundle_names):
        sidecar_info["bundle_ids"][f"{bundle_name}"] = ii + 1
        dps[self.bundle_idxs[bundle_name]] = ii + 1
    dps = {"bundle": dps}
    self.sft.data_per_streamline = dps
    if self.this_tracking_idxs is not None:
        for ii in range(len(self.this_tracking_idxs)):
            self.this_tracking_idxs[ii] = int(self.this_tracking_idxs[ii])
        sidecar_info["tracking_idx"] = self.this_tracking_idxs
    return self.sft, sidecar_info