Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Any battle damage this card inflicts to your opponent is treated as effect damage instead.
--墓守の従者
--Gravekeeper's Vassal
local s,id=GetID()
function s.initial_effect(c)
	--battle damage to effect damage
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_BATTLE_DAMAGE_TO_EFFECT)
	c:RegisterEffect(e1)
end