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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def vrrp_config_change(app, instance_name, priority=None, advertisement_interval=None, preempt_mode=None, accept_mode=None):
 """change configuration of an instance. None means no change. """

    config_change = vrrp_event.EventVRRPConfigChangeRequest(
        instance_name, priority, advertisement_interval,
        preempt_mode, accept_mode)
    return app.send_event(vrrp_event.VRRP_MANAGER_NAME, config_change)