@staticmethod
def JumpToken(obj, eng, callbacks, exc_info):
    """Action to take when JumpToken is raised."""
    step = exc_info[1].args[0]
    if step > 0:
        eng.state.token_pos = min(len(eng), eng.state.token_pos - 1 + step)
    else:
        eng.state.token_pos = max(-1, eng.state.token_pos - 1 + step)
    eng.state.callback_pos_reset()
