def METHOD_NAME(self):
    # Should miss the collision
    sim = rebound.Simulation()
    sim.integrator = "leapfrog"
    sim.collision  = "direct"
    sim.dt = 10
    sim.add(r=1,x=0)
    sim.add(r=1,x=3,vx=-1)
    sim.init_megno()
    sim.particles[-1].x = np.nan # test that collisions with variational particles not being checked
    sim.integrate(10)