def METHOD_NAME(integrator):
    opt = {'atol':1e-10, 'rtol':1e-7}
    sys1 = qutip.QobjEvo(0.5*qutip.qeye(1))
    inter1 = integrator(sys1, opt)
    inter1.set_state(0, qutip.basis(1,0).data)
    sys2 = qutip.QobjEvo(-0.5*qutip.qeye(1))
    inter2 = integrator(sys2, opt)
    inter2.set_state(0, qutip.basis(1,0).data)
    for t in np.linspace(0,1,6):
        expected1 = pytest.approx(np.exp(t/2), abs=1e-5)
        assert inter1.integrate(t)[1].to_array()[0, 0] == expected1
        expected2 = pytest.approx(np.exp(-t/2), abs=1e-5)
        assert inter2.integrate(t)[1].to_array()[0, 0] == expected2