# import numpy as np
# import pytest
# from astropy import units as u
# from matplotlib import pyplot as plt
# from numpy.testing import assert_allclose

# from einsteinpy import constant
# from einsteinpy.metric import RobertsonWalker

# _c = constant.c.value


# def test_calculate_trajectory(
#     pos_vec,
#     vel_vec,
#     time,
#     M,
#     era,
#     tuning_param,
#     k,
#     start_lambda,
#     end_lambda,
#     OdeMethodKwargs,
# ):
#     cl = RobertsonWalker.from_spherical(pos_vec, vel_vec, time, M, era, tuning_param, k)
#     ans = cl.calculate_trajectory(
#         start_lambda=start_lambda,
#         end_lambda=end_lambda,
#         OdeMethodKwargs=OdeMethodKwargs,
#     )
#     ans = ans[1]
#     testarray = ((ans[:, 4] ** 2) / (_c * 2)) - (
#         (ans[:, 5] ** 2 + ans[:, 6] ** 2 + ans[:, 7] ** 2) / (_c ** 2)
#     )
#     print(testarray, len(testarray))


# test_calculate_trajectory(
#     [306 * u.m, np.pi / 2 * u.rad, np.pi / 2 * u.rad],
#     [0 * u.m / u.s, 0 * u.rad / u.s, 951.0 * u.rad / u.s],
#     10000 * u.s,
#     1 * u.g,
#     "md",
#     1.0,
#     0,
#     0.0,
#     0.1,
#     {"stepsize": 0.0001},
# )
