def METHOD_NAME(self):
    sim = rebound.Simulation()
    sim.add(m=1.)
    sim.add(m=0.,x=1.,vy=100000.)
    sim.integrator = "ias15"
    sim.dt = 1.234567
    sim.integrate(1.234567)
    y = sim.particles[1].y
    ys = 1.234567*100000.
    self.assertAlmostEqual((y-ys)/ys, 0., delta=1e-10)