Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Cannot be Summoned unless you control a face-up "Rod of Silence - Kay'est". This card is unaffected by Spell effects and cannot be targeted for attacks, but does not prevent your opponent from attacking you directly.
--ガーディアン・ケースト
--Guardian Kay'est
local s,id=GetID()
function s.initial_effect(c)
	--sum limit
	local e1=Effect.CreateEffect(c)
	e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE+EFFECT_FLAG_UNCOPYABLE)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_CANNOT_SUMMON)
	e1:SetCondition(s.sumlimit)
	c:RegisterEffect(e1)
	local e2=e1:Clone()
	e2:SetCode(EFFECT_CANNOT_FLIP_SUMMON)
	c:RegisterEffect(e2)
	local e3=e1:Clone()
	e3:SetCode(EFFECT_SPSUMMON_CONDITION)
	c:RegisterEffect(e3)
	--immune spell
	local e4=Effect.CreateEffect(c)
	e4:SetType(EFFECT_TYPE_SINGLE)
	e4:SetCode(EFFECT_IMMUNE_EFFECT)
	e4:SetProperty(EFFECT_FLAG_SINGLE_RANGE)
	e4:SetRange(LOCATION_MZONE)
	e4:SetValue(s.efilter)
	c:RegisterEffect(e4)
	--atk
	local e5=Effect.CreateEffect(c)
	e5:SetType(EFFECT_TYPE_SINGLE)
	e5:SetCode(EFFECT_IGNORE_BATTLE_TARGET)
	e5:SetProperty(EFFECT_FLAG_SINGLE_RANGE)
	e5:SetRange(LOCATION_MZONE)
	e5:SetValue(1)
	c:RegisterEffect(e5)
end
s.listed_names={95515060}
function s.cfilter(c)
	return c:IsFaceup() and c:IsCode(95515060)
end
function s.sumlimit(e)
	return not Duel.IsExistingMatchingCard(s.cfilter,e:GetHandlerPlayer(),LOCATION_ONFIELD,0,1,nil)
end
function s.efilter(e,te)
	return te:IsSpellEffect()
end