def METHOD_NAME() -> Tuple[gtsam.Values, List[gtsam.BinaryMeasurementUnit3]]:
    """"Returns global rotations and unit translation directions between 8 cameras
    that lie on a circle and face the center. The poses of 8 cameras are obtained from SFMdata
    and the unit translations directions between some camera pairs are computed from their
    global translations. """
    fx, fy, s, u0, v0 = 50.0, 50.0, 0.0, 50.0, 50.0
    wTc_list = SFMdata.createPoses(gtsam.Cal3_S2(fx, fy, s, u0, v0))
    # Rotations of the cameras in the world frame.
    wRc_values = gtsam.Values()
    # Normalized translation directions from camera i to camera j
    # in the coordinate frame of camera i.
    i_iZj_list = []
    for i in range(0, len(wTc_list) - 2):
        # Add the rotation.
        wRi = wTc_list[i].rotation()
        wRc_values.insert(i, wRi)
        # Create unit translation measurements with next two poses.
        for j in range(i + 1, i + 3):
            # Compute the translation from pose i to pose j, in the world reference frame.
            w_itj = wTc_list[j].translation() - wTc_list[i].translation()
            # Obtain the translation in the camera i's reference frame.
            i_itj = wRi.unrotate(w_itj)
            # Compute the normalized unit translation direction.
            i_iZj = gtsam.Unit3(i_itj)
            i_iZj_list.append(gtsam.BinaryMeasurementUnit3(
                i, j, i_iZj, gtsam.noiseModel.Isotropic.Sigma(3, 0.01)))
    # Add the last two rotations.
    wRc_values.insert(len(wTc_list) - 1, wTc_list[-1].rotation())
    wRc_values.insert(len(wTc_list) - 2, wTc_list[-2].rotation())
    return wRc_values, i_iZj_list