def METHOD_NAME(t, x, u, params):
    # Get the parameters for the model
    l = params.get('wheelbase', 3.)         # vehicle wheelbase
    phimax = params.get('maxsteer', 0.5)    # max steering angle (rad)
    # Saturate the steering input (use min/max instead of clip for speed)
    phi = max(-phimax, min(u[1], phimax))
    # Return the derivative of the state
    return np.array([
        math.cos(x[2]) * u[0],            # xdot = cos(theta) v
        math.sin(x[2]) * u[0],            # ydot = sin(theta) v
        (u[0] / l) * math.tan(phi)        # thdot = v/l tan(phi)
    ])